2The process of converting gas into solid state directly is calledsublimationChange of state from solid to gas and back to solid is called sublimation. Fusion is from solid to liquid and liquid to solid is solidification. Liquid to gas to evaporation whereas gas to liquid to condensation.

3The technique used for separating drug from blood isChromatographyChromatography is a separation technique used to separate the different components in a liquid mixture. It was introduced by a Russian Scientist Michael Tswett. Chromatography involves the sample being dissolved in a particular solvent called mobile phase. The mobile phase may be a gas or liquid. The mobile phase is then passed through another phase called stationary phase. The stationary phase may be a solid packed in a glass plate or a piece of chromatography paper.

4What is the molecular mass of nitric acid63Formula of Nitric Acid is HNO3 and molecular mass will be calculated as sum of atomic mass of the constituents as 1+14+3*16=63

5Elements are defined as the number ofproton it possess

6What is a tissue?A groups of cells which is meant for a specific task is called tissueTissue and Division of Labour: In complex organisms, different tasks are carried out by different organs and organ systems. Tissues are the first step towards division of labour in complex organisms. A groups of cells which is meant for a specific task is called tissue.

7The motion is said to be uniform when the acceleration iszeroThe acceleration has be zero means the speed not increasing and motion takes place at a uniform speed with any change in the speed. However, in actual practice some acceleration is required to compensate the retarding force arising out due to surface/air friction.

8An artificial satellite is moving in a circular orbit of radius 42250 Km and takes 24 hours to complete one revolution. What will be its linear velocity?3073 m/sLinear velocity = 2*r/t = 2*22*42250*1000/7*24*60*60=3073 m/sec

9The SI unit of large weight of a body isNewtonWeight is the gravitational force acting on a body and is determined as m*g with unit as that of force i.e. Newton. SI unit of mass is Kg. The weight of a body remains constant throughout on earth as g is constant, meaning thereby that W is proportional to m and for this reason, weight is used commonly for mass.

10The work done in lifting 1 Kg of mass for a distance of 1 m is equal to9.81 JoulesThe force acting on the body down ward is 1 Kg*g=9.81 N and the work done is F*S=9.81 N-m or Joule

11The disease not caused by virus istuberculosisThe disease caused by virus is one in which the virus dies by itself and no medicine services the purpose.

12Potassium permanganate when dissolved gives what color?pinkThe chemical formula is KMnO4 is having highly oxidising property and used wherever such property is to be used such as fruit preservation, water treatment, analytic purpose.

13Matter exists in how many states?5Matter exits in five state namely solid, liquid, gas, plasma and Bose Einstein Condensate. In day to day affair, we observe only three states i.e. solid, liquid and gas

14Percentage of oxygen in air is around0.21The composition of air is nitrogen = 78$, oxygen = 20.9%, argon = 0.8%

15Avogadro number is a fixed number equal to 6.022*1023 defines the number of moles of what in 1 mole of any substanceallThe number of particles i.e. atom, molecules or ions present in 1 mole of any substance is fixed, with a value of 6.022*1023. This is an experimentally obtained value and called Avogadro Constant. The mass of 1 mole of a particular substance is always constant. It is equal to sum total of relative masses of atoms or molecules in grams.

16Each living cell has got a certain specific components within it calledorganelle

17Plant tissues are of two types of which one is Meristematic and what is the second one?Permanent TissuePlant tissues are of two main types, viz. meristematic tissue and permanent tissue. The distracters mentioned are types of meristematic type of tissue.

18In a motion, the average velocity found to same as that of the average speed. The motion is said to bea straight lineThe straight line motion is having velocity and speed same. In circular motion, the direction vector is always changing. Here distractor of all in fourth option Is used to create confusion in the mind of candidate.

19The tendency of the object to remain at rest or keep on moving with the same velocity is defined byInertiaInertia is the mass of the object. For any motion we always take mass of the object and when under the influence of gravity, the force applied on the object is weight i.e. mg.

20The value of gravitational acceleration at poles ishigherOur actual earth has a polar radius of about 6.3568 x 106 m and slightly longer equatorial radius of about 6.3781 x 106 m. Using those values, it can be calculated that gravitational accelerations of about 9.87 m/s2 for the poles and about 9.80 m/s2 for the equator of our perfect spinning earth.

21An object moving with a velocity of 5 m/sec possess an energy of 25 J. What will be its energy if the velocity is doubled?100 J1/2*m*25=25; m = 2 Kg, 1/2*2*100=100 J

22The disease not cased by bacteria isPolioThe bacterial infection requires medication to kill the bacteria causing the disease for which anti-bacterial drugs are generally given

23Diffusion is a processintermixing of particle of different matters on their own

24Why do inside of car glass gets mist while driving during rain?it is the condensation of inside humid air on the glass whose temperature is lowDuring rains the relative humidity is very high. The respiration process of passenger produces water and increases the level of humidity inside the car. When car moves, due to wind flow over windscreen, the water droplets evaporate make glass colder on which the water vapours condensates.

2What is the weight of carbon atom when one mole carbon atoms weighs 12 grams and Avogadro constant is 6.022*1023?5.018*1022Avogadro Constant/Weight of one mole of atoms of a substance. Another weight to rule out other distracters is that weight of one carbon atom will be less than weight of one mole.

3There are three features of every cell of which two are namely nucleus and cytoplasm, What is third one?plasma membrane

4Animal tissues are of how many types?4Animal tissues are of four types, viz. epithelial tissue, connective tissue, muscular tissue and nervous tissue.

5Rate of change of velocity determinesacceleration

6For a uniformly accelerated objects, the distance travelled is proportional to the square oftimeWe know S=1/2*a*t*t. This law was derived by Galileo while observing falling bodies.

7A mass and diameter of a planet is about 1200 and 6 times less as compared to earth, than the gravitational acceleration as compared to earth will be1/33th timesg=GM/R2 we get gp=GMp/Rp2 and ge=GMe/Re2 and gp/ge=MpRe2/MeRp2 = 36/1000 or gravitational attraction at planet will be 1/33 times that on earth

8Two stones of mass 5 Kg and 10 Kg are dropped from 100 m height tower touches the ground with what ratio of velocity1Velocity gained is dependent only the height and not on mass

9This is the not the disease which spreads through airTyphoid

10Which of the following is not a matter?cold

11A saturated solution whichwhich cannot dissolve more soluteIt is solute dissolved in solvent and the stage beyond which no more solute can be dissolved is called saturated solution.

12Metalloid are elements which arecombination of metal and oxygenThe elements which show intermediate properties between those of metals and non-metals are called metalloids such as boron, silicon, germanium etc.

13What the mass of four moles of Aluminium when its atomic mass is 27?1084*27=108 gram

14Hypotonic solution is the one of which water concentration ishigher water concentration than cellThere are three type of solutions namely hypotonic, isotonic and hypertonic where the water concentration in the solution is higher, same and lower as compared to that of inside the cell. The water is exchanged through the process of osmosis. For gases, the diffusion process is used for exchange of gases.

15Chromosomes are made up ofDNA and Protein

16The area of the curve with velocity and time taken on the axis describes thedistance travelledArea is multiplication of v=d/t and t; thus giving the distance travelled.

17A person travelling on a high speed boat will move outwardly when it takes a sudden turn is due toinertiaThe body will fall outwardly because of its tendency to move straight instead moving on the path of the boat which changed suddenly.

18Pressure exerted by any solid, liquid or gas isdirectly proportional to force and inversely proportional to the area of crossectionPressure is given as F/A; for nails area is less so that it can pierce into the body

19Two stones of mass 5 Kg and 10 Kg are dropped from 100 m height tower touches the ground with what ratio of kinetic energy2The velocity gained is same by the stone having two times mass will gain double the kinetic energy

20Microbes causing AIDS is not spread bymosquito bite causing transmitting virus through blood

21LPG stands forLiquefied petroleum gasIt is a petroleum gas compressed to liquid state. When knob of the cylinder is opened, it evaporates and starts flowing through tube and used for burning

22A suspension solution is calledheterogeneous mixtureSuspension is a heterogeneous solution in which the solute does not dissolve but remain suspended in the solvent and is visible with naked eye.

23A combination of elements showing the properties of each of the constituent is calledmixture

24The distribution of electrons as given in Bohrs model in different orbits is given by the formula2n2Electrons revolves in orbits with first orbit named as K and than L, M, N etc with numbering n as 1,2,3,4 etc. and number of electrons is 2,8,18,32 etc. with maximum minimum 8 number of electronics in the outermost orbit except number 1.

2The proteins and lipids essential for building the cell membrane, are manufactured byThe proteins and lipids essential for building the cell membrane, are manufactured by

3Velocity-time relation of any motion is given by the equation; when distance, initial and final velocity, time are s, u, v and t.v=u+at

4The measurement of inertia is by measurement ofmassIf inertia is not related to mass, than inertia is same for a train engine and a bullock cart which is not correct

5An object weighs 36 g in air and has a volume of 8.0 cm3. What will be its apparent weight when immersed in water? Density of water 1000 Kg/m3.28 gmThe density of 1000 Kg/m3 is actually 1 gm/cm3 and hence the weight of displaced water is 8 gm and the resultant weight will be 28 gm.

6A cart rolls down a hill and gains a KE equal to velocity of 4 m/sec. If the cart is pushed with an initial speed of 3 m/sec, the speed at the end of the hill will be5 m/secInitial KE=1/2*m*(3)2 and KE gained is 1/2*m*(4)2 and the total energy will be 1/2*m*(5)2; equal to speed of 5 m/sec

7How is the speed of sound in solids as compared to gases?it is more in solidThe speed of sound is more in solids varying 4700 m/s to 6420 m/s in brass to aluminium whereas it is of the order of 1284 m/sec in hydrogen, 346 in air and 213 in Sulphur dioxide.

8Why it is difficult to make anti-viral medicine?viruses have few biochemical mechanism and uses human cell for their process

9CNG standscompressed natural gasIt is a natural gas compressed to liquid state. When knob of the cylinder is opened, it evaporates and starts flowing through tube and used for burning

10A colloidal solution is aheterogeneous solutionA colloidal solution is similar to suspension but the particle size is very small not visible from naked eye such as milk. It is a heterogeneous solution where the milk particles can be separated out.

11A combination where the constituents elements can be separated easily is calledmixture

12Valancy of an element as per Bohr-Bury model is defined as thethe definite combining capacity of an element either by gaining or losing electronOption 2 and three does not give the correct interpretation as option 2 does not answer the accepting tendency of an atom and similarly option 3 does not answer giving up tendency of electron.

13Endocytosis is the process by which the cell membranegets it food from external environmentThe flexibility of the cell membrane also enables the cell to engulf in food and other material from its external environment . Such processes are known as endocytosis and amoeba acquires its food through such processes.

14Which of the following tissues has dead cells?Sclerenchyma

15Distance-time relation of any motion is given by the equation; initial and final velocity, time are s, u, v and t.s=ut+1/2at2

16The force applied on a body to result change in its motion is defined as theAllF=m(v-u)/t or m*a and all the option is same

17The water from a container filled with water leaks through a hole in parabolic trajectory which depends on the water coloum above the leak hole. This container now had a free fall. What happens to the trajectory of water?it stops coming out from the containerThe parabolic trajectory is due to weight of water column above the hole. During free fall the water is weightless and therefore, water will not be flowing out.

18Rate of doing work is calledPowerPower takes into account how fast a work can be done. Unit of power is Work Done/time or Joules/sec

19The time interval for clear hearing of echo shall be at least0.1 secThe sound we hear a little later is called a echo and the sensation of out speech remains in our brain for about 0.1 sec. It is therefore, necessary that the echo shall be heard after an interval of more than 0.1 sec for echo to be heart. The reflection surface shall be located at a distance of more than 17.2 m.

20A century ago, a person who survived small pox illness makes a voluntary group to serve the person suffering with small pox why?he has already developed resistance against the small pox virusVirus makes a protection cell of the human body, damages it but in the mean time vaccination for the virus also get developed making the person immune towards this virus. Such person when survives, also develops immunity towards such viruses.

21How the LPG smells?it is odourlessLPG is odourless gas is odourless but a stench agent is added to assist in leak detection. The odorant used is Ethyl Mercaptan. Ethyl Mercaptan, which possesses a distinctive and unpleasant odour, is the odorant used . Ethyl mercaptan is also selected because it is non-corrosive, has a low sulphur content and possesses a boiling point very near that of LPG.

22what is tyndall effect?it is scattering of light through colloidal or suspended particle in gas or liquid.The Tyndall effect, also known as Tyndall scattering, is light scattering by particles in a colloid or particles in a fine suspension. It is named after the 19th-century physicist John Tyndall.Vortex rings are plentiful in turbulent flows of liquids and gases, but are rarely noticed unless the motion of the fluid is revealed by suspended particlesas in the smoke rings which are often produced intentionally or accidentally by smokers.

23What is the effect of solubility of salt in water with increasing temperature?it remains almost constantSolubility of salt remains almost constant at the level of 36-37 gms in 100 gm of water.

24Mass number of an element is defined asthe sum total of proton and neutral present in the nucleusMass number is the sum total of proton and neutral and atomic number is the number of protons.

2Girth of stem increases due tolateral meristem

3Distance-velocity relation of any motion is given by the equation; initial and final velocity, time are s, u, v and t.v2-u2=2*a*d

4A constant force of 10 N is applied to an object weighing 5 kg and moving with a initial velocity of 5 m/sec for 10 secs. What will be its final velocity?25 m/secWe know F=m(v-u)/t or[ F*t/m]+u=v or [10*10/5]+5 = 25 m/sec

5A 2 m cube is filled with water up to a height of 1 m exerting a force at the base of the container. A 50 Kg uniform crossection object is immersed in the tank of which 1/5 the portion floats. What will be force now at add to the base of the container?50There is buoyant force of 10 Kg and 40 Kg of weight which will act downward. But the reaction of the buoyant force will also be on the base therefore net additional of force will be 50 Kg.

6A 10 kW motor works at full rating for 10 Hours working at an efficiency of 90% will consume energy of100 kWh10 kW motor working at full rating will draw energy of 10(kW)*10(hours)=100 kWh

7Reverberation of sound is undesirable in a auditorium and is controlled byusing soundabsorbent material

8Rabies virus is spread throughdog bite

9Melting point of ice is273.16 K

10This is not a solid-gas colloidalbutter

11A standard to measure the atomic masses is given asmass of 1/12th part of the mass of one atom of carbon-12 isotopesIn 1961, for a universally accepted atomic mass unit, carbon-12 isotope was chosen as the standard reference for measuring atomic masses. The relative atomic masses of all elements have been found with respect to an atm of carbon-12 atom.

12Isotopes of an element is defined as elements havingsame atomic number but different mass numberIsotopes of Hydrogen are protium, deuterium and tritium having same atomic number of one but mass number of 1,2 and 3. Similarly, carbon and chlorine has one more isotopes each 14C6 and 37Cl17. The atomic structure is written as Mass Number/Formula/Atomic number

13Inheritance of parental features are stored in the form of DNA which stands forDeoxyribo Nucleic Acid

14Cartilage is not found inear

15A train weighing 500T is travelling at speed of 90 Km/hour. Brakes are applied to stop the train within a distance of 1 Km. What should be the uniform de-acceleration for which brakes be applied?0.312 m/sec2Convert speed into SI units i.e. 90*1000/60*60=25 m/sec, now use the formula v2-u2=2*a*s i.e. 25*25=2*a*1000 or a=0.312 m/sec2.The mistakes usually done is not following the units or formula etc. Weight of the train is given as a distractor with no relevance in the answer

16A truck weighting 7 T starting from rest rolls down a hill with a constant acceleration and travels a distance of 400 m in 20 sec. The force acting on the truck will be14000 NS=1/2*a*t*t; we get (400*2/20*20) = a i.e. 2 m/sec/sec. The force acting will be m*a or 7000*2=14000 N

17Lactometer is the device used for the measurement ofpurity of milk

18What property of wave changes when it changes its media from air to water?Speed and Time periodv=f*, frequency does not change and when v changes, will also change

19The sound of the heartbeat of patient using stethoscopes reaches to the ear of the Doctor throughmultiple reflection of sound in the tube

20Greenhouse effect is caused by the atmospheric excess concentration ofOzoneCarbon dioxide absorbs heat resulting into rise of temperature. If it so happens, the snow at mountain will start melting raising the level of water in the sea. The environmentalist are planning to hold the level of carbon dioxide in the environment to the level existing at the beginning of 20th century.

21What is dry ice?solid form of carbon dioxideDry ice is the solid form of carbon dioxide and primarily used as cooling agent. Its advantage include lower temperature than that of water ice and not leaving any residue. It is useful for preserving frozen foods, ice cream etc. when mechanical cooling is not possible.

22Cream is separated from milk by the process ofchurningBoiling leaves khoya, filtration no effect, churning makes the heavy particle to separate out

23Chemical formula of Sodium Oxide isNa2OThe vacancy of Na is one and that of Oxygen is 2 ; and therefore the formula of Na2O

24isobars are defined as the atoms ofdifferent elements with different atomic numbers which same mass numbersThe atomic number of calcium and argon is 20 and 18 but both has the same mass number of 40

2Nutrient-poor soils can be planted with which plant to enrich them with nitrogen?legumeProcessing, or fixation, is necessary to convert gaseous nitrogen into forms usable by living organisms. Some fixation occurs in lightning strikes, but most fixation is done by free-living or symbiotic bacteria. These bacteria have the nitrogenase enzyme that combines gaseous nitrogen with hydrogen to produce ammonia, which is then further converted by the bacteria to make its own organic compounds. Some nitrogen fixing bacteria, such as Rhizobium, live in the root nodules of legumes (such as peas or beans). Here they form a mutualistic relationship with the plant, producing ammonia in exchange for carbohydrates. Nutrient-poor soils can be planted with legumes to enrich them with nitrogen. A few other plants can form such symbioses. Nowadays, a very considerable portion of nitrogen is fixated in ammonia chemical plants.

3Find the distance travelled by a train starting from rest in 50 sec of which acceleration for first 30 sec is 1.12 Km/hour/sec and next 20 sec by 0.9 km/hour/sec.190 mConvert acceleration SI units i.e. 1.12 Km/hour/sec = 1.12*1000/3600 m/sec/sec or 0.311 and 0.9*1000/3600=0.25 m/sec/sec. S=1/2[0.311*30*30+0.25*20*20]or 1/2[279.9+100] = 190 m

4The fixed end of the spring balance is fixed on the wall and another end connected to another spring balance which is pulled with a force of 50 N. The deflection on each spring will be25, 25The force exerted on each of the spring is equal and opposite to each other called action and reaction force in compliance to Newtons third law of motion.

5Two bricks namely A and B are placed in water at a depth of 2 m and 5 m respectively. Which brick will require more downward force to hold the brick in position?Both sameThe buoyant force will be same for both the bricks which is the difference between the top and bottom pressure, and therefore, the buoyant force acting on the body to be applied to keep the brick in position is same.

6What happens to speed of sound when it changes its media from air to water?increasesThe speed of sound increases because it travels due to transfer of energy from molecule to another. In water, the molecules are closely held.

7The audible range of sound for human beings is between20 Hz-2000 HzThe hearing range of normal human being is 20 Hz to 2000 Hz. Children of age 5 years can hear sound up to 25 KHz.

8Ozone depletion in the outer atmosphere will result inpassage of ultra violet rays of the sun to earth

9Dry ice issolid carbon dioxideCarbon dioxide stored at very high pressure in solid state which gets converted directly to gaseous state on decrease of pressure to 1 atm.

10The method used for the separation of common salt from Ammonium Chloride issublimationAmmonium chloride evaporate on heating, and thus mixture is heated with ammonium chloride is collected as gas. Solubility will not work as both dissolves in water.

11What is the chemical formula of Aluminium ChlorideAlCl3The valance of Al is three and that of Chloride is one ; and therefore the formula of AlCl3

12How the mass number which is an integer represents the mass number of chlorine which is taken as 35.5?due to existence of isotopes in the ratio of 1:3Chlorine exists freely with isotopes of 35 and 37 mass number in the ratio of 1:3; and thus average mass number is 35.5 when a sample is taken.

13The cells organism which lack a nuclear membrane are calledprokaryotesIn some organisms such as bacteria, the nuclear region is poorly defined due to absence of nuclear membrane and are called prokaryotes. The cells having a nuclear membrane are called eukaryotes.

14Which of the following is not a green house gas?Ammonia

15A stone is thrown vertically upward with a velocity of 5 m/sec. How much distance it will travel if the value of g is 10 m/sec/sec?1.25h=v*v/(2g)=25/2*10=1.25 m

16An object weighing m kg moving with a velocity of v on application of force N Newton, the momentum of the object will bemvMultiplication of mass with the velocity is called the momentum of the object. The application of force will result in change of its velocity and change of momentum

17A person is walking on a frozen lake and suddenly hears cracking sound of the ice. What is the same best same option for the person?to lie flat on the ice and crawl towards the bankThe most important requirement is to reduce the pressure on the frozen ice to prevent further cracking of the ice. By lying down, the pressure or force at a point reduces thus preventing a chance to reduce chance of further propagation of cracking. The effective pressure on the ice is minimized through option 4.

18What happens to the speed of sound with increasing temperature?increasesWith increasing temperature, the molecules of air get agitated and having less inertia resulting transfer of sound signal from one molecule to another easy.

19Ultrasound are not used for the following applicationremote controlThe other application of ultrasound waves is in medical application such as echo-cardiograph and getting images of internal organs of human beings and measurement of distance, direction and speed of under water objects.

20What is responsible for the depletion of ozone layerCFC compoundsCFC escapes to the higher environment and reacts with ozone

21What happens to the size of the air bubble rising from bottom of the pool towards top of the pool?size increasesThe external pressure reduces as the bubble goes up, therefore internal pressure results in increasing the size of the bubble

22How the intensity of sound varies when the distance between the source and ear is doubled?becomes one fourthThe intensity of sound varies with distance as I=P/4r2

23The vibrations of sound wave are amplified by three bones of which two are called hammer and anvil. Name the third onestirrup

24Three containers are filled with water up to same height with same base area but reducing volumetric capacity. Which container will exert maximum force at the base?All SameThe force at the bottom depends on the height of water column and not the volume of the water I.e. *g*h

1Combination reactions are those in whichtwo or more substances reacts to form one produceCombination reaction is one in which all the substances combines to form one product.

2Chemical name of the product used for white washing of walls isCa(OH)Ca(OH) is an aqueous solution which combines with CO present in the environment dries to form CaCO

3Higher pH is an indication of higherOH ion concentrationpH scale is from 0 to 14 and middle value is neutral. Lower on the scale is increasing concentration of Hydrogen ion and increasing is OH ion concentration

4The process in which Hydrogen is passed over CuO and CU + HO are formed is calledredoxIn this process oxidation and reduction both are taking place where hydrogen is oxidised and CuO is reduced.

5Calcination is a process used in extraction of metal from its ore in whichore is heated strongly in the presence of excess airThe process of calcination is used for extracting metals which are middle in the activity series. It required strong heating with excess air for roasting and limited air for calcination.

6Saturated hydrocarbons are also called asalkanes

7The formula is of functional groupaldehyde

8Maximum number of electrons that can be accomodated in a shell depends on the formula2nThe shells are K =[ 2*(1)]=2; L = [ 2*(2)]=8; M=[ 2*(3)]=18; N=[ 2*(4)]=32 etc.

9Which of the following is not a part of the female reporductive system in human beingsvas deferens

10The normal blood pressure is120/80

11What is coranary artries?it supplies blood to heart muscles

12The xylem in plants are responsible fortransport of water

13Spherical mirrors having reflecting surface curved outwards is calledconvex mirror

14You need concave lens to correct the eye visionfor myopia

15Why is the danger signal colour is red?the red colour of the white light scatters the minimumThe wavelength of blue colour is minimum whereas that of red colour is maximum. For this reason, it is the blue light which scatters most and red color the least by fog and smoke, and can be seen of same colour from distance.

16Electrical energy is the most preferred mode of energy because it isall

17Resistivity of wire depends directly on thealways constantResistivity is the property of the material and remains constant and is calculated by =R*A/l

18The iron filings near a magnet will alignparallel to the magnetic field

19The phenomenon of electromagnetic induction discovered by Faraday relates to thatrelative motion between a coil and magnetic field produces current in the coil aElectromagnetic induction is a result of relative motion. AC produces varying magnetic field which induces emf in the nearby coil.

20Which one is not a necessary requirement while planning a thermal power plant?it should be near electrical loadIt is not necessary to locate the power plant near load as it is reasonably OK to transport electricity as compared to transportation of coal and water which are required continuously and effect economy of power generation.

21During fission process while harnessing energy for peaceful purpose, the mass of the radio-active heavy elements undergoes changes thatit reducesThe reduction of mass is converted into electrical energy by the equation E=m*c; and as the speed of light is very high, loss of one unit of atomic mass produces 931 MeV of energy where 1eV=1.60210^(-19)

1Exothermic chemical reactions are those in whichheat is releasedAlways remember exothermic means exhale or out and endothermic means inhale or intake

2Pb(NO) when heated forms the following productsPbO, NO, OPb(NO) is called lead nitrate and when on heating releases the products given at option 2. The best way to find the answer is by balancing the equation.

3pH range of human body is6.5-7.0pH scale is 0 to 14 with neutral at 7. Zero is highly acidic and 14 highly basic. pH of human body is slightly acidic becuase of the need of acids to consume food.

4Bag of chips is flushed with nitrogen gas toprevent oxidation of anti-oxidants used in the oilUsually substances which prevent oxidization are added to foods containing fats and oil. Keeping food in air tight containers helps to slow down oxidation. This is the reason of flushing out oxygen and filling nitrogen to prevent oxidation.

5Electrolytic process is used for extracting of metals lyinglow in the activity seriesMetals with very high reactivity are extracted by electrolysis of the molten ore. They cannot be extracted by heating, oxidation or reduction.

6Unsaturated hydrocarbons with one or more double bonds is calledalkenesRemember all single bonds alkanes, one or two double bonds alkenes and one triple bond alkynes. Alkines does not exists and a distractor.

7The formula is of functional groupketone

8The elements have the outermost orbit complete filled up are calledinert gasesWith no vacancy to fill up the outermost orbit, the gases are unable to exchange any electrons and thus non-reactive.

9The anther containspollen grains

10The function of oesophagus is totransport food from mount the stomach

11The blood from the lungs is dealt in the heart inright artriumThe blood flows from right artrium to right ventricle and to lungs. Oxygen rich blood than comes to left artrium and move to the body through left ventricle.

12The autotrophic mode of nutrition requiressunlight

13In a concave mirror, the size of the real and inverted image is same, than the object if lyingat the center of curvature point

14What type of vision correcting lens is generally required by every one in old ageconvexDuring old age, the near point gradually recedes away and find it difficult to see nearby objects and this defect is called presbyopia and corrected using convex lens to bring back the image on the retina which earlier was forming far away from retina.

15The human eye forms the image of an object at itsretinaCheck different parts of the eye.

16A current of 0.5 A has passed through an incandescent lamp for a period of 10 minutes. What is the total charge passed through the lamp300 CQ=i*t; 0.5*600=300 C

17The SI unit of electrical resistivity isOhm-mIn case of doubt use the =R*A/l to work out the unit as Ohm-m. It can be written as Ohm-cm but than it cannot be SI unit.

18The magnetic field around a current carrying conductor will always bein a circle around the conductor

19The working principle of a fuse isJoules Heating effect

20Bio-mass fuels areAllRenewable source of energy is one which can be renewed within a short period and therefore, plant (all plants incl. vegetable), animal and sewage is produced continuously in the system and a good source of energy except the reason that the quantity is less and only small power plants can be built on such system.

21The major hazards of nuclear power generation isAllThe limitations are not only these three but includes not availability of Uranium raw material also.

1Respiration is anexothermic process

2Silver chloride turning into grey substance in sunlight is calledendothermic reactionWhen it is mentioned sunlight, means it is endothermic reaction.

3Rain water is called acid rain when its pH isless than 5.6Pollutant gases like carbon dioxide and Sulphur dioxide mix with rain to make it acidic and if the pH is less than 5.6, than it is called acid rain.

4Anodising is a process during whicha thick layer of aluminium oxide is formed on Al to protect it from oxidation

5Silver article becomes black when exposed in air due to formation ofSilver Sulphide

6Unsaturated hydrocarbons with one or more triple bonds is calledalkynes

7The formula is of functional groupcarboxylic acid

8Metalloids are elements whichexists in semi-metal stateThere are 18 groups and 7 periods in a periodic table. The elements on the left are metals, in between like Si, Ge, B, As etc are metalloids and extreme right are gases or non-metals.

9Life process is defined as a process in which theAll

10What is the function of mucus in stomach?to protect the inner lining of the stomach from the action of acidsThe air passage to lungs is also protected by mucus lining

11How many chambers are there in the heart of fish?twothe blood is pumped through two chamber heart to gills, get oxygenated and than directly passes to rest of the body

12Which of the following is a plant hormone?cytokinin

13A concave mirror produces a highly enlarged and real image. Where is the object locatedat F

14The middle colour of the seven colour spectrum isgreenRemember VIBGOYR for the seven colours and Green is the middle colour.

15The least distance of distinct vision for a young adult with normal vision is about25 cm

16What is the approximate range of speed of charge in a conductor when current is flowing through it?1mm/secDrift velocity is very small but the effect of voltage is at the speed of electro-magnetic wave travelling through the conductor near to the speed of light.

17The resistivity of an alloy is as compared to parent metalsmoreThe resistivity of conductors is of the order of 10 where as alloy of these material is in the range of 10 ohm-m.

18A current is flowing through a conductor from bottom to top, the magnetic field will beanti-clock wise in vertical planeUse RH rule; where thumb shall position in the direction of the flow of current, than the direction of fingers will give the direction of the magnetic field.

19Why there is a energy crisis when it can neither be created nor destroyed?energy is available in usable and non-usable form and the crisis is of usable form

20Anaerobic micro-organisms which breaks down complex compound of cow-dung slurrydoes not require oxygenAnaerobic process does not require oxygen

21Biodegradable substances are those which areallBiological process are natural process. The non- biodegradable items can be broken under the influence of high temperature and pressure.

1Decomposition of vegetable matters into compost isan exothermic processDuring decomposition heat is released and thus it is exothermic reaction

2Endothermic reaction uses energy in any of the formallEnergy not only in the form heat but in any form including electric current used during a reaction is called endothermic reaction. Electric current is also used.

3Human stomach produces which acid for the purpose of digestionHCl

4Which of the metal is most reactivePotassiumThe order of reactivity is K, Na, Ca and Mg, Al, Zn, Fe, Pb etc.

5Copper article becomes greenish when exposed to environment due toformation of Copper carbonate layer

6Graphite is allotropes of carbon used in pencil and softness is derived due tohexagonal strucutreThree atoms of carbon are held with hexagonal structure and the fourth by a double bond. One layer of structure slips over the other making the pencil to work.

7How many carbon atoms and which functional group forms Butanone4-ketoneRemember Carbon 1-Methane, 2- Ethane, 3- Propane, 4- Butane; and e is replaced by one means it is ketone therefore 4-ketone.

8The metals existing on the left side of a periodic table areelectro-positive in natureThe electropostive elements is having a tendency to loose electrons easily.

9What are common chemical reactions keep on going in living organism?oxidising and reducing

10The food from the stomach moves first tosmall intestine

11What is the function of blood platelets?plug the blood leaksPlatelets helps in plugging leaks by clotting the blood at the point of injury. These are small size of about 20% of the blood cells and in the ratio of 1:10 to 1:20 ratio.

12The gap between two neurons is called asynapse

13If the speed of light in vacuum is c and in medium v, than the refractive index of the medium is given asc/vThe refractive index of any medium other than vacuum is always greater than one. The speed through any medium will always reduce as compared to vacuum in which it is the maximum

14The splitting of light into seven colours is calleddispersionSplitting of colours is called dispersion. Refraction is bending of light depending on the media and reflection is returning of the light beam back. Whereas scattering results on the size of the particle. The higher size particle scatters light of mainly longer wavelength.

15Depletion of ozone layer at higher layer of atmosphere may resultnon-shielding of UV radiation reaching earthOzone is a molecule of three atoms of oxygen with chemical formula of O and formed in the higher level atmosphere by breaking oxygen molecule into oxygen atoms which combine with oxygen molecule to form ozone. This ozone protects UV radiation passing to earth which causes skin cancer.

16Electric potential is defined aswork done per unit chargeV=W/Q is the fundamental equation of potential derive from the work done by a unit charge for moving from place to another in an electric field.

17Resistivity of the insulators is of the order of10^16

18The magnetic field inside a long straight solenoid carrying current issame at all points

19What is fossil fuel?which is available below the earth surfaceFossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms

20India produces how much electrical energy from wind15000-25000MWIndia wind energy production is about 20000MW with future scope of about 45000 MW. The biggest wind farm is at kanyakumari of 380 MW capacity.

21The reaction of NaCl+AgNO AgCl+NaNO is adouble displacement reactionCl of Na is replaced by NO and NO of Ag is replaced by Cl means double displacement.

1Decomposition reaction is such in whichsingle reactant breaks down to two or more simple products

2Common name of CaOCl isbleaching powderBleaching powder is made using Calcium Hydroxide and chlorine resulting bleaching powder and water.

3What is required by human body to get rid of pain due to high acidity?Magnesium HydroxideMilk of magnesia is generally used to treat high acidity in the stomach.

4The reagent used to dissolve gold and platinum isAqua regiaAqua regia is a freshly prepared mixture of concentrated HCl and HNO. It can dissolve Gold and Platinum but none alone

5Condition for rusting of ferrous material is the existing ofmoist airRusting takes place when air and water both attacks together the ferrous surface.

6The property of carbon to form bonds with other atom of carbon is calledcatenationPetanation and tetanation are not any property and options are only distractors. Tetravelency is a property

7Which elements were selected by Mendeleev for studying the chemical property for finding the position in the periodical table?Oxygen and HydrogenOxygen and Hydrogen are very reactive and forms oxide and hydride with each elements easily.

8Which of the statement is not correct when going from left to right across the periods of periodic table?the atoms lose their electrons more easilyThe number of electron keep on increasing as we go from left to right on a period.

9Name the constituent which is not a part of the photosynthesis processoxygenThe constituents are CO. Water, Chlorophyll and sunlight which makes carbohydrates providing energy to the plant.

10Terrestrial animals are those which lives onland

11The role of kidney in a human body is toremove nitrogenous products from bloodFunction of kidney is remove waste products from blood on lines similar to as CO removed by lungs.

12Image formed by a plane mirror is alwaysvirtual and erect

13Power of a lens is given as1/fPower of a lens is given in dioptre and given as f because when combining two lenses it can be added as a normal sum.

14During dispersion of light through a prism, which light bends the leastredRed light bends the least and violet the maximum

15Depletion of ozone layer at higher layer of atmosphere is a consequential effect ofrelease of chlorofluoro carbons into the environmentOzone is a molecule of three atoms of oxygen with chemical formula of O and formed in the higher level atmosphere by breaking oxygen molecule into oxygen atoms which combine with oxygen molecule to form ozone. This ozone protects UV radiation passing to earth which causes skin cancer.

16Resistance of any wire depends directly on thelength and inversely on the area of corssectionAlways remember the formula R=*l/A and be careful about the distractors. The purpose of distractor is distract you from the correct answer and make you commit mistakes

17Four resistances of value 1.5 ohms, 1.510 ohms, 2.610 ohms and 1.710 are connected in parallel, the net resistance will be1.49 ohmsNever attempt to such a long calculation in multiple choice questions and use logic. The resistance will always be slightly lower than 1.5 ohms and cannot be greater than 1.5 ohms.

18Flemings left hand rule is used to find out the direction ofdirection of force produce on a current carrying conductorFlemings left hand rule is find out the force where as right hand rule is for generated current. In LHR, thumb points towards motion when first and middle finger points towards field and current which are 90 degree to each other.

19This is not a renewable source of energy?NuclearRenewable source of energy is one which keeps on renewing at a short cycle whereas non-renewable source of energy is renewable with a time period of 1000 to million years.

20This is not a limitation while planning a wind power house to augment the power need of an establishmentback up facilityWind farm is not a stand-alone system and requires a back up when generation is not enough. But in case of need of augmentation of power generation, some source is already available.

21Purity of Gold is defined in carat and 24 carat is the purest form. 22 Carrot gold will bePurity of Gold is defined in carat and 24 carat is the purest form. 22 Carrot gold will beAlong with what is mentioned, chrome plating, galvanising, tinning are also used for this purpose.

1The chemical symbol of commonly known product lime isCaOCaCO is called lime stone and when heated releases CO and CaO called lime. The reaction is called endothermic as it absorbs heat energy

2The chemical name of baking soda used in the kitchen during frying of cooking items isNaHCO

3Plaster of Paris when mixed with water givesGypsumPlaster of Paris in dry form is CaSO.HO and when mixed water it makes gypsum CaSO.2HO which is dry. Plaster of Paris is used for support fractured bones.

4Calcination is a process used in extraction of metal from its ore in whichore is heated strongly in the presence of limited airThe process of calcination is used for extracting metals which are middle in the activity series. It required strong heating with excess air for roasting and limited air for calcination.

5Stainless steel is an alloy of Iron withNickel and Chromium

6Carbon compounds with same molecular formula but different strucutres are calledstructural isomars

7How Mendeleev predicted existing of elements which were not discovered by that timegaps in the periodical tableOption 3 is very well known answer but all is a major distractor to confuse the candidate.

8The brain is responsible forall

9The pressure in arteries is than in veins.greater

10The basic function of blood is not to transportAllBesides these the other function of blood is to perform the task of delivering the nutrients and glucose generated by the organs of the digestive system to the other parts of the body including the liver. It is the function of blood to first take the oxygen processed by the lungs to all the cells of the body and then to collect the carbon dioxide from the cells and deliver it to the lungs.

11Hemodialysis is an artifician process to perform the function of vital organkidney

12Spherical mirrors having reflecting surface curved inwards is calledconcave mirror

13The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?between p and f

14Formation of rainbow is result of following phenomenon taking place on water droplet one after anotherrefraction, dispersion, internal reflection, refractionThe tiny water droplets existing in the atmosphere first refracts the light and than disperse. The disperse light undergoes total internal reflection and refracts back to air.

15How much sun energy is used by plants to to make food through the process of photo-synthesis?0.01

16Copnduction of any wire depends directly on thearea of crossection and inversely on lengthAlways remember conductance is inverse of resistance.

17The relation for resistive heating is given byAllThese are different way writing the joules law of heating using ohms law. Always be careful, All is most of the time a correct answer, but a major distractor also. By inserting one wrong option and another All, there is possibility of you clicking All.

18Split rings are used in a electric motorto connect positive and negative terminal of power supply

19This is a limitation for planning a hydro power generating plantenvironmentHydro power is much less running cost but higher capital cost but overall benefit. It is thus economical but for environmental issues has to be handled very carefully.

20This is an advantage of solar power plantit does not require back up facilityIt does not have rotating parts as required in wind, biomass and hydro. Solar cells are placed on the panel and all cells receives energy and does not require focussing arrangement. It is a stand-alone system but requires back up to take care when sun is under shadow or not there at all.

21For electrolytic refining of metals, the impure metal is usedanodeAnode is made of impure metal. It looses pure metal and impurities into the electrolyte. The pure metal deposited on the cathode and the impurities either get dissolved in the electrolyte or settles down.

1A bar of steel is having linear coefficient of expansion and young modulus as 1.210 /K and 210*10 N/m. What stress will develop for 10 degree rise in temperature?2.4*10 N/mStrain = 1.2*10*10= 1.2*10 and stress is strain multiplied with young modulus of elasticity- 2.4*10 N/m. Be careful about the unit as its change is generally used as distractor

2A bob of mass 0.40 Kg hung from the ceiling of a room by a string of 2m long is set into oscillation. The speed of the bob at its mean position is 1 m/s but the string get cut when it is at its extreme position. What is the trajectory of the fall of the bob?VerticalThe velocity at the extremities is zero, therefore, the bob will fall vertically down. If the string get cut at the middle, it will move in a parabolic trajectory towards the direction of motion. The numerical values have been given to distract you. Be careful, when the answer does not have numerical values, means no calculations are required.

3How the blood pressure in human being at feet compares with that in brain?more at feet as compared to brainGenerally the height of heart is 1.3 m and that of brain is 1.7 m. The force of gravitation makes the pressure different at brain and foot level. Taking the air density as 1.0610 kg/m, the pressure at foot and brain is 26.8 and 9.3 kPa when pressure at heart is 13.3 kPa (100 mmHg)

4Which property of water helps for survival of plant and animal life in pond and sea during very low temperature?density of ice is maximum at zero degree than water and it floats on the surfaceThe density of water is maximum at zero degree and less at higher and lower temperature. When frozen, it floats being denser than water and provide thermal protection for the sea life. Option 4 is main distractor with density low but wrongly answered, and if you dont read the answer carefully, may tick 4

5It is observed that the free falling body through gas or liquid experience a viscous force which is proportional tovelocity, radius of body and viscosity of mediumIt is observed that the viscous force depends on viscosity eta of the medium, radius of the sphere, velocity and is in the opposite direction to the motion. This is also called Stokes Law F=6a. A rain drop falling in air initially accelerates at the level of g but viscous force also increases with increase of v and finally settles at constant velocity and called terminal velocity which remains constant unless viscous force changes in between. You should keep the formular on the rough paper to avoid any influence of distractor.

6The process of regelation is possible with this substanceIceRegelation is the phenomenon of melting under pressure and freezing again when the pressure is reduced. Many sources state that regelation can be demonstrated by looping a fine wire around a block of ice, with a heavy weight attached to it. Regelation was discovered by Michael Faraday. Regelation occurs only for substances, such as ice, that have the property of expanding upon freezing

7Angstrom is the smallest measurement unit. What is its value?10 mm1 Angstrom is equal to 10mm, unit developed to measure atomic and molecular distances. Distraction is given by unit; suppose you remember the answer in meter, may like to make a mistake.

8The speed of rotation of an automobile wheel at the point of contact as observed by a stationary person isequal or near to zeroThe speed at the point of contact is nil or near to zero. If the speed is r, than the wheel is slipping and the speed of the top particles of the wheel is 2r. (-r) is impossible.

9For what advantage I (eye) crossection is used for Railway trackWeb resist shear force and bending moment by flangeWeb resist shear force whereas flange helps in countering the bending moment. Thermal expansion is taken care by providing transition gap at the end of the rail.

10The ratio of Young and Shear Modulus for the same material is in the range of2.5 to 3Shear modulus is small and about one third of young modulus.

1The voltmeter and ammeter used for the measurement is having an error of 100 plus/minus 5 and 10 plus/minus 0.2 for voltmeter and ammeter respectively. These ammteres are used for the measurement of resistance, what error is expected?7%During division and multiplication, the percentage errors are added. Percentage error of voltmeter is 5% and ammeter is 2% therefore, total is 7%.

2A box weighing 1 Kg is lying on the floor of a vehicle having coefficient of friction 0.3. The vehicle acceleration in m/sec shall be restricted to what level for the box to remain static? (g=10m/sec)3The frictional force act in opposition to the acceleration equal to 1*10*0.3=3N. The force of acceleration shall never exceed 3 N for the box not to move. Therefore, acceleration shall be limited to 3/1 or 3 m/sec

3SI unit of surface tension isN/mThere is general tendency to think that the unit of tension is N/m where as it is N/m due to the tension prevailing at the line of interface between metal and liquid. In terms of energy it is also given as J/m. It is important to keep the formula on your sketch

4Equation of continuity relates to theflow of liquidEquation of continuity is a statement f conservation of mass in flow of incompressible fluids and an important equation of Area*Velocity at any point in liquid flow remains constant.

5Knowledge of Reynolds number is helpful in determininglaminar or turbulent behaviour of fluidOsborne Reynolds number R =d/ determines the tendency of fluid flow. When it is less than 1000, the flow is laminar and more than 2000, it is turbulent and between 1000 to 2000, it unsteady.

6Sublimation is the process in whichsolid changes to gas directlyThe changes from solid state to vapour state without passing through the liquid state is called sublimation and the substance is aid to sublime. Dry Ice and Iodine are sublime substances.

7Electron Microscope has to capability to measure least distances of the range of1 AngstromElectron Microscope of 0.6 A has been developed. The figures are generally given ascending or descending order. Sometime it is given at random. Dont get influenced with the order.

860 when converted into radian will be0.017460 is equal to 0 and equal to /180 = 0.0174 radians. The distraction here is 60 and there is possibility that one can go for the calculation of 1

9Plastic materials are thosewhich does not regains its original position after the applied force is removedPlastic material deforms and does not regain back its original position after the deformation force is removed. The material which regains it original position are called Elastic material. The distracter is that all the answers start with the language which does not or does regain and makes the candidate to confuse himself.

10Two helical springs of spring constant k1 and k2 are attached with a mass in parallel, what will be total spring constantk=k1+k2Spring constant behaves similar to capacitor for connection in parallel or series. when connected in parallel, the spring constant adds. Answer two is for when connected in series.

1A jet travelling at a speed of 500 Kmph ejects a projectile at a speed of 1500 Kmph. What is the speed of the projectile as observed by an observer on ground?1500The observer will see relative speed of 1500-500=1000 Kmph.

2A constant retarding force of 50 N is applied on an object weighing 20 Kg and moving with a speed of 15 m/sec. The object will come to stop after how much time?6The retarding momentum to be balanced with the momentum of the object. The retarding momentum is F*t or 50*t=20*15; therefore t= 6 sec.

3Why a paper clip of iron floats on the surface of water?This is because the surface tension between the surface of paper clip and water which supports the weightThe weight of the pin is very small and It is the surface tension of the water which supports this weight. If the weight is more than the surface tension, than only it may penetrate the water surface.

4Bernoulli Principle relates toconservation of energyEquation of continuity relates to conservation of mass whereas Bernoulli Principle relates to conservation of energy namely pressure, potential energy due to gravity and kinetic. Giving options in this manner creates doubt.

5Higher specific heat of a substance is an indication that when an amount of heat is suppliedthe temperature of the substance will rise slowlyQ=msT means specific heat and T is inversely proportional therefore, higher specific heat means less rise in temperature. The specific heat of water is 4186 as compared to 900 and 500 of Al and Carbon.

6This is an advantage of frictionRheostat brakingRheostat braking is when rotational mechanical energy is converted into electrical and wasted across a resistance. It is not related to friction. Dont forget that here All is a distracter to confuse.

7Which one is a vector quantity?WeightWeight is a vector whereas mass is a scalar. All others are scalar we all know

8The famous Einstein equation is written wrongly forgetting where to insert speed of light c as m=m/[(1-v). What is the correct equation?m=m/[(1-v/c)The correct formula can be assessed by balancing the unit which shall be M for both side and that is the reason c will appear in the denominator of v. Now it may be kept in the numerator as in option 1, than the term will become imaginary as the v can never be more than c.

9When a body is subjected to deformation force, a restoration force is developed in the body which is also calledStressRestoring force per unit area is called Stress. Remember strain is unit less, Y is a relation and constant for a body and Newton law is applicable for external actions.

10A spring of spring constant k and m does simple harmonic motion in a frictional less horizontal plane. The angular velocity is given byk/mx(t)=ACos(t+); v(t)= -Asin(t+); a(t)= -Acos(t+); a(t)= -Ax(t) orF(t)= m* a(t)= -m or -kx(t) were k= -m or =k/m

1A cricket ball is thrown at a speed of 28 m/sec at an angle of 30 degree. To what height it will go?10 mh={vSin}/{2*g) and other formulas in this regard are time to reach this distance = vSin/g, horizontal distance covered is called range and given by [v Sing2/g]

2A person is weighing 70 Kg on a weighing scale lying on the floor of a lift. The lift moves downward at an acceleration of 5 m/sec. What will be the reading on the weighing scale? (g=10m/sec)35When the lift is standstill, downward force 70*10 N is balanced by equivalent reaction. When the life moves downward with acceleration of 5*70 N, than the scale will experience a reaction of only 700-350 N equal to 35 Kg. Similarly when the lift is accelerating upward, the scale will read 105 Kg.

3The relationship curve for converting degree centigrade to Fahrenheit isa inclined straight lineThe equation for the conversion of degree into Fahrenheit is given by [(Tf-32)/180]=Tc/100 which is straight line with intersection of 32 on Tf scale and slope of 1.8

4Magnus effect relates todynamic lift due to spinningThe difference in the velocities of air results in the pressure difference between the lower and upper faces and there is net upward force on the object. Ball moving with spin, lift of air plane and aerofoil are explained by this effect.

5The ratio of volume expansion to linear expansion on heating is aroundthreeThe linear expansion is only in one direction where volume expansion is in three direction therefore the net effect on volume is three times. The coefficient of linear expansion of Al and Brass is 2.510/K and 1.810/K whereas volume is 7 and 610/K.

6A body is moving from rest in unidirectional under the influence of constant power. The displacement in time t is proportional tot*tWe know d=ut+at and P=M*a*d/t or a=M*t/d and u=0 we get d= [M*t/d]t or d*d proportional to t*t or t*t

7A box is kept in a lorry moving with a constant speed. Suddenly the driver applies brakes. What happens to the box?The box will move in the forward direction of motion if the frictional force is less than braking force.The box was moving in the forward direction along with the lorry. With application of brake, the box will continue to move in the same direction even the brakes are applied but will resisted by the frictional force between box and the lorry surface. If the frictional force is more it will not move and if it is less, than it will slide. On similar argument, answer number 3 and 4 are relevant when the lorry starts accelerating.

8What is the acceleration experienced by an object lying at the edge of a circular plate and rotating at a constant speed?it will experience acceleration towards the centre of the circular plateThe acceleration of an object moving with uniform speed v in a circle of radium R experiences acceleration of magnitude v/R directed towards centre and is called centripetal acceleration, a term proposed by Newton.

9When ultimate strength and fracture point on stress-strain curve are close by, the material is calledbrittleWhen point 4 and 5 are closer, than the material is brittle

10Why it is easy to roll a cylinder as compared to rectangular block of same weight and on the surface with same coefficient of friction?There is just one point of contact and no relative motion therefore point does not experience any frictionThe speed at the point of contact is almost negligible and thus experience very little friction. The static and kinetic friction is zero and the body shall continue to roll with constant velocity but there is rolling friction which will retard the speed.

1A truck starts from rest and accelerate at 2m/sec. After 10 second a person standing at 6 meter height, drops a stone. What is its velocity?20 m/sec horizontalVelocity is a vector quantity and to be expressed with direction. The direction in the present case is same as that of moving vehicle as per fist law of Newtons law of motion

2A person weighing 50 Kg lifts a mass of 25 Kg by a rope from a well once without pulley arrangement and next time with pulley arrangement. What is the reaction on the ground when lifting with pulley arrangement? ( g = 10 m/sec)250 NWhen lifting the weight through the pulley, the reaction force on the pulley will W+T=2W i.e. 500 N. The reaction on the surface will than become 250 N.

3The relationship of linear expansion of long rod due to rise in temperature is given asL/L is proportional to tIt is the change of per unit length proportional to rise in temperature. If the length is doubled, than rise will also double for the same rise in temperature.

4Coefficient of viscosity for a fluid is defined as the ratio ofshearing stress/strain rateThe strain in a flowing fluid increases with time continuously and experimentally found depend on rate of change of strain or strain rate.

5Why the earth surface warms up quickly during day and cools quickly during night in desert?due to low specific heat of sandThe substance having low specific heats up fast. The specific heat of sand, concrete, iron is 830, 880 and 490 J/Kg C respectively

6A pump on the ground floor is required to pump 30 meter cube water to a 40 m height over head tank in 15 minutes. What power of pump is required when the efficiency of pump is 33%.40 kWEnergy required to mgh and power is mgh/t. In the present case weight of water is 30 meter cube and density1000 Kg/meter cube and we get (30*1000*10*30)/(15*60*0.33)= 40 kW

7Two objects A which is heavy and B which is lighter are thrown from the top of a 100 m building at the same time. Which object will reach the ground first?Both at the same timeBoth the objects will reach at the same time because weight has no effect on the average speed of travel.

8For any arbitration motion in space, the following relation for calculation average velocity holds truev (average)= [r(t)+r(t)](t-t)Average stands for average of quantity over the time interval(t-t)

9A stationary person is watching another person in a convex mirror moving at a constant speed towards him. He will observe the speedincreasing as he approaches the mirrorIn the standard equation of mirror 1/v+1/u=1/f, if we put the value of u at different time, the image location v is not uniform but keep on reducing therefore the image will appear moving fast on approach

10Visible light spectrum wavelenth is between400-700 nmVisible light spectrum shall be gone through with information where radio, microwave, x-ray and gamma rays lies.

1A metal rod held in hand when rubbed with a silky cloth will accumulateno chargeThe charge accumulates only on insulators. On conductor the charge conducts through human body to earth. If it is held with wooden handle, the charge will accumulate on the conductor.

2A silver wire has a resistance of 2.1 at 27.5C and 2.7 at 100C. What is the temperature coefficient of resistivity of silver?.0039CR(27.5)=2.1 ohms. R(100)=R(27.5)[1+t]; 2.7=2.1[1+(72.5)]; = 0.2857/72; = .0039C. Observer that unit has been used as a distractor which sometime missed by many. When change of temperature is in degree, the unit cannot be Kelvin.

3A current carrying conductor produces magnetic field and the law to calculate the magentic field at a point is given byBiot-Savart LawBiot-Savart law relates the magnetic field to the magnitude, direction, length and proxmity of the electric current. Oersted Law states that The line integral of the magnetic field , around any closed curve C, is proportional to the total current I, passing through any surface bounded by the curve.

4In a concave mirror the image is formed real and inverted when the object is placefurther away from the focal pointReal and inverted image is formed when the object is placed further away from the focal point. At focal point, the image is formed at infinity and from focal point to the centre, it will be erect and virtual behing the mirror.

5Melting of ice is aIsothermal ProcessSince temperature during melting of ice remains constant at 0 degree hence it is isothermal process

6Two charges of value Q are placed at a distance of r. Another charge of (-Q/3) is required to be placed in between the line joining the two . For equilibrium, where the charge shall be placed?r/2

7An infinitely long ladder is having a resistance of 1 ohm of each arm of each of the rectangle formed in its consutrction as shown. What is it equivalent resistance?1+ 3Assume the equivalent resistance to be R and as it is infinitely long, than the equivalent resistance will be R when seen from uniform configuration and can be drawn as follows. The resistance now calculated will be option 2. Also notice that the equivalent resistance cannot be more than 3 thus negating option 3 and 4.

8The image magnification m in optics is given byAllEvery one remembers the formula of first options when v and u are given, but by using the mirror equation of 1/v+1/u=1/f, the relation can be worked out in terms of v &f and u&f.

9The difference between molar specific heat at constant volume and constant pressure isalways negativeCp-Cv=R where R is universal gas constant

10Multiplication of permittivity and permeability results interesting relation of1/c=1/c

1This is one of the standard method of creation of chargeCharge cannot be createdCharge cannot be created. It only travels from one location to another. Gold leaf Electroscope is used to measure the force between charges and van de graph generator is for accumulating the charge. The same is the function of capacitor where charge is allowed to accumulate.

2n resistors each of R ohms are first connected in series and than in parallel. The ratio of the resistance in series by parralel will benSeries combination=nR, Parallel combination R/n. Therefore ratio is n. The mistake is likely to committed to write parallel combination as n/R, thus working out the relation as R

3A physical significance of a virtual image formed in optics is thatit can be seen by naked eye but cannot be projected on screen

4Heat supplied is equal to work done is the outcome which law of thermodynamicsfirst

5A charged particle of charge q is moving at a velocity of v parallel to the magnetic field B, it will be accelerated by a forceit will continue to move unaffectedA charge particle moving in a magnetic field experiences Lorentz force given by vector product of v and B as F=q(vxB) or F=BqvSin; where if is the angle of motion with respect to B. If it is zero, the force is also zero and maximum and perpendicular to B and v if it is 90. for any other value it will be helix.

6A battery of inernal resistance e and emf of E supplies power to resistance R. The power drawn is maximum whenr=RMaximum Power= E*E/4R

7Ratio of refrective index of one medium 1 in respect of other medium 2 is given by the relation/It is important to remember wrt i.e. Option 2 will be correct if we have to working out the ratio of 2 wrt 1. The third option is based on the velocity of light in two different medium.

8The difference between molar specific heat at constant pressure and constant volume is given byRCp-Cv=R where R is universal gas constant

9For conversion of galvanometer into voltmeter, you will requirea high series resistance with galvanometerVoltmeters are connected in parallel to the circuit whose voltage is to be measured therefore, it should draw very little current and therefore, a high series resitance is required.

10Van de Graaff generator are used to produceMillion Volt Electric Potential

1Suggest way to shield a sensitive measuring instrument from a strong electrostatic field environment.provide a metallic conducting enclosure around itBy providing a conducting material screen, the field inside become zero

2How the resistivity of alloys as compared to parent metals?increasesThe mobility of charge particle reduces with alloying of material

3When two thin lenses joins together, the focal length of the lenses combination will be given as1/F=1/f+1/fDiopter scale was adopted for opthalmologist as it simply adds the diapoter of one lense with that of another. The inverse of focal length is taken as Diapoter otherwise this question has no significance.

4The ratio of Cp and Cv for a dia-atomic gas isfive/threeCp/Cv==f+2/f where f is 3,5, etc for monatomic and dia-atomic gas.

5A capacitor is made consisting of two dielectric of thickness t & t and dielectric constant of K & K. What will be its equivalent dielectric constant?*A/[ t/K + t/K]C=*A/t; here the thickness will now become t+ t if the dielectric constant is same. Now the effective thickness will now become t/K + t/K and effective capacitance will become C=*A/[ t/K + t/K]

6A battery of internal resistance e and emf of E supplies power to resistance R. The current drawn is maximum whenR=0The maximum current will be when the resistance is minimum as inernal resistance is fixed and cannot be zero, it will be maximum when R is zero.

7Why does the sun looks red at the time of sunset?the light from sun encounter large atmosphere where the blue light is scattering more leaving mostly red light to travelThe light which scatters is not visible and red light having minimum scattering will be more prominently visible.

8The gas equation of an ideal gas isPV=RTGas equation is very standard equation PV=nRT; and demonstrate all relations with the variables in any thermodynamic system.

9Glittering of diamond is due toto total internal reflection of lightAbsorption, reflaction and dispersion has different property.

10Two incandescent bulbs of 100 and 200 W are connected in series by a Voltage source of V. Which bulb will glow brightly?100 WWhen connected in series, the net power is given by 1/P=1/P+1/P; and therefore, higher power lamp will have less contribution. Sine i is same, hence P is in proportion to the resistance. For higher wattage, R is small.

1How is the charge accumulated on the aeroplane during flight taken care?conductive material is added in the wheel tyre to discharge the accumulated charge immediately on landingDue to air rubbing with the body of the aeroplane, charge accumulates on the surface of the aeroplane and it is necessary to discharge it immediately on landing otherwise it will try to discharge through the bodies which will come in contact with it. The tyres are made with some parts of conductive material. Discharge is not possible in the sky because of the same potential of all bodies.

2A current is flowing through a conductor with varying crossection from place to place. Which of the quantity remains constant through out the conductor?current

3Dioptre is used as unit of measurement of optical power and is equal to1/fDioptre scale has been developed to make the calculation for ophthalmologist simpler as optical power in dioptre is added when two thin glass are placed close to each other. It means that dioptre power of +5 when placed along with +2 dioptre power will make it to +7 dioptre.

4105 Calories of heat is required to raise the temperature of 3 mole of a gas from 30C to 35C at constant pressure. How much heat will be required to raise by 10C at constant volume.75Let Qp=Cptm and Qv=Cvtm; we get Cp/Cv=Qp/Qv==1.4(mono-atomic gas). Qv = Qp/1.4 = 105/1.4 =75 calories.

5Energy stored in a capacitor is given byE=CVEnergy stored is given by Q/2C=CV=QV

6The voltage applied across a battery of emf E and internal resistance r for charging isV=E+irThe supply voltage has to be more than the emf of the battery and shall compensate for the voltage drop across the internal resistance i.e. Ir.

7The speed of light in air and water are 3 and 2.2510 m/sec respectively. A person standing near a water pool of 1 meter depth will observe the height to be0.75 mThe apparent depth is given by Real depth* Speed of light in water/speed of light in air. If a person looks towards a object from inside the pool which is 1 m height will find it at 1.33 meter high.

8The constant in isothermal process isTemperature

9The constant in isobaric process isPressure

10Splitting of light into its constituent colours is calleddispersion of light

1A person decided to build 1 F capacitor. What size of plates are required if the gap between the two plates is kept 0.5 cm. The value of =8.854*10 (-12))565 KmC=*A/d; A= C*d/; A= 1*0.005/8.854*10 (-12) = 565 Km. Size of the plates are of very large size for building 1F capacitor. Dont do precise calculation and try to match the answer.

2What happens to the thermal coefficient of resistivity of pure metal when alloyed?decreases

3A person is walking in front of a plane mirror at a speed of 0.3 m/sec. What is his speed relative to the image speed?0.6 m/secAs the person is walking towards the plain mirror at a speed of 0.3 m/sec, his image is walking towards him at the same speed therefore, for relative motion, the speed adds.

4This is not a microscopic variable in a thermodynamic system of gasesEntropyThe macroscopic variables are P,V,T and mole or mass

5The ratio between the surface charge density and permittivity isElectric field between the two platesE=/ where is surface charge density

6For conversion of galvanometer into ammeter, you will requirea small in parallel to galvanometerFor conversion of a galvanometer into a ammeter, you have to bypass maximum of current away from the galvanometer, and for that you need a parallel small resistance also called shunt in parallel.

7The critical angle for total internal reflection reduces with theincrease in refractive indexThe critical angle for total internal reflection is given by sin(1/); cannot be less than one and for greater values, critical angle will keep on reducing.

8The constant in adiabatic process isAmount of heat

9The constant in isochoric process isVolume

10Irreversibility in thermodynamic process arises due toallIrreversibility is where all the energy input cannot be converted back