2015-16 -...

Physics is the natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. It intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined.

Ali Raza Fauji Foundation Higher Secondary

School (Inter College) Talagang June 9th, 2015

Tuesday

SECOND YEAR PHYSICS

Objective Portion, Short Questions,

Memory Tricks, Graphs, Conceptual Questions,

Experiment Based Questions, Labeled Diagrams

2015-16

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 12: ELECTROSTATICS

Physics Class: XII

(Objective) Time: 30 min Marks: 17

Scheme (15)

Weightage = 12% MCQ’s = 2 Short Questions = 4 Extensive Question = 1(Theory)

Section-I (Objective Type Questions-17)

Q: 1 Encircle the right option from the following. (6 x 1 = 6)

(i) The number of free electrons in one coulomb charge is:

(a) 6.2 x 1020 (b) 1.6 x 10-19 (c) 6.2 x 1018 (d) zero

(ii) If atomic number of copper is 29, the contribution of electrons per atom in the block of copper will be:

(a) 2 (b) 3 (c) 0 (d) 1

(iii) Charge on an electron was determined by:

(a) Ampere (b) Maxwell (c) Millikan (d) Thompson

(iv) The unit of energy density of electric field is:

(a) J C-1 (b) J V-1 (c) J m3 (d) J F3

(v) If a charged body is moving against the electric field, it will gain _______ energy.

(a) Potential (b) Mechanical (c) Kinetic (d) Electrical Potential

(vi) Speed of charging and discharging of a capacitor depends on resistance and:

(a) Charge (b) Capacitance (c) Current (d) Potential Difference

Q: 2 Fill in the blanks with appropriate word. (6 x 0.5 = 3)

(i) Value of dielectric constant for air or vacuum is ____________.

(ii) The magnitude of charge on an electron is ____________.

(iii) Electric field intensity due to a point charge at distance r is equal to ____________.

(iv) The copying process is called ____________.

(v) For the computation of electric flux, surface area should be ____________.

(vi) One electron volt is equal to ____________ joules.

Q: 3 State the following statements as true or false. (6 x 0.5 = 3)

(i) Electron energy is one electron volt when it is accelerated through a potential difference of two volts.

______

(ii) When a surface is held parallel to E then flux is zero. ______

(iii) The force in medium of relative permittivity εr is given by Fmed=F/ εr. ______

(iv) The relation (∆V/∆r=V/d) represents electric flux. ______

(v) SI unit of electric flux is NC-1m2. ______

(vi) Photocopier and the inkjet printer are examples of the current electricity. ______

Q: 4 Pen down reason for the justification of following statements. (5 x 1 = 5)

(i) Electric lines of forces never cross.

________________________________________________________________________________

(ii) Electrons tend to go to region of high potential.

________________________________________________________________________________

(iii) εr = Cmed/Cvac.

________________________________________________________________________________

(iv) Electric field lines originate from positive charges and end on negative charges.

________________________________________________________________________________

(v) The minimum value of charge on electron is equal to 1.6 x 10-19 C.

________________________________________________________________________________

ALI RAZA KAMAL

ALI RAZA KAMAL

(Subjective) Time: 3:00 hours Marks: 83

Section-II (Short Questions-44)

Q: 5 Write short answers of following questions. (8 x 2 = 16)

(i) Define electrostatics. Compare it with current electricity.

(ii) State Coulomb’s law.

(iii) Write down the vector form of Coulomb's law.

(iv) Show that Coulomb force is a mutual force.

(v) Define dielectric medium. What is the effect of dielectric medium on electrical force, when it is placed

between two point charges?

(vi) Show that following has same units.

kq

r2 =

F

qo

(vii) What do you know about ‘electric field intensity’? Also, derive its expression.

(viii) Find out the expression of electric field intensity due to point charge.


(i) Write down the properties of electric lines of force.

(ii) What do you know about electric flux? Describe its different cases.

(iii) Find out the expression of the electric flux passing through a surface enclosing a charge.

(iv) Describe the dependence of shape of close surface on electric flux passing through it.

(v) State and explain the Gauss’s law.

(vi) In which case Coulomb’s force is greater when glass and mica are placed between two charges?

(vii) Define following

(a) Electric Potential Difference

(b) Absolute Electric Potential

(viii) Prove that

1 Volt

Meter= 1

Newton

Coulomb


(i) Define electron volt. Prove that:

1 eV = 1.6 x 10-19 J

(ii) Describe the similarities and difference among electrical and gravitational force.

(iii) Define capacitor and capacitance of capacitor.

(iv) Show that two equal charges apply equal but opposite force on one another.

(v) Define dielectric constant of a substance.

(vi) How the electric polarization of dielectric result in the enhancement of capacitance of capacitor?

Section-III (Essay Type-24)

Q: 8 Attempt FOUR questions. (4 x 4.5 = 18)

1. Explain applications of Gauss’s law.

2. Calculate electric potential at a point due to a point charge.

3. Calculate a charge on an electron by Millikan’s Method.

4. What is capacitance of parallel plate capacitors?

ALI RAZA KAMAL

ALI RAZA KAMAL

Q: 9 Attempt THREE numerical. (3 x 2 = 6)

1. A point charge q = -8.0 x 10-8 C is placed at the origin. Calculate electric field at a point 2.0 m from the

origin on the z-axis.

2. Determine the electric field at the position r = (4i + 3j) m caused by a point charge q = 5.0 x 10-6 C placed

at origin.

3. Find the electric field strength required to hold suspended particle of mass 1.0 x 10-6 kg and charge 1.0

µC between two plates 10.0 cm apart.

Section-IV (Practical-15)

Q: 10 Pen down the answers of following questions. (5 + 10 = 15)

A. Write down procedure to determine the internal resistance of galvanometer by half deflection method.

B. Write brief answers of following questions:

(i) What is shunt resistance? What is purpose of using it?

(ii) Why the galvanometer gives half deflection when both keys are closed?

(iii) Define galvanometer and its types.

(iv) Give the effect of temperature on resistance of a substance.

(v) What is an accurate method to find the internal resistance of galvanometer?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 13: CURRENT ELECTRICITY

Physics Class: XII


Scheme (10)

Weightage = 8% MCQ’s = 1 Short Questions = 3 Extensive Question = 1(Numerical)



(i) The charge carriers in electrolyte are:

(a) protons (b) positive ions (c) negative ions (d) Both b and c

(ii) A balanced Wheatstone bridge is used to determine:

(a) e.m.f (b) potential difference (c) current (d) unknown resistance

(iii) An instrument which can measure potential without drawing any current is called:

(a) ammeter (b) voltmeter (c) galvanometer (d) potentiometer

(iv) For an open circuit:

(a) Є = Vt+ ir (b) Є < Vt (c) Є > Vt (d) Є = Vt

(v) The colour strip on carbon resistor from extreme left are yellow, black and red its resistance is:

(a) 4 kΩ (b) 400 Ω (c) 40 kΩ (d) 40 Ω

(vi) A student has five resistances each of value is 1/5 ohm. The minimum resistance that can be

obtained by combining in parallel is:

(a) 1/50 Ω (b) 1/25 Ω (c) 1/10 Ω (d) 5 Ω


(i) The current through a resistor of 100 Ω when connected across a source of 220 V is ____________.

(ii) Reciprocal of resistivity of a material is called ____________.

(iii) The resistance of a meter cube of a material is called its ____________.

(iv) Electrical energy is measured in ____________.

(v) Terminal potential difference of a battery is greater than its e.m.f. when ____________.

(vi) The tolerance of silver band is ____________%.


(i) For electroplating, we use D.C. source. ______

(ii) Maximum power output of a battery is Pmax= E/4r2. ______

(iii) Potentiometer can be used as an ammeter. ______

(iv) Resistivity of a material depends on nature of material. ______

(v) Electromotive force is closely related to inductance. ______

(vi) Heat generated by a 40 W bulb in one hour is 144000 J. ______


(i) The resistance of a conductor rises with temperature.

________________________________________________________________________________

(ii) Bends in a wire does not affect its electrical resistance.

________________________________________________________________________________

(iii) The terminal potential difference of a battery decreases when the current drawn from it is increased.

________________________________________________________________________________

(iv) Filament resistance is lower in a 500 W, 220 V light bulb than in a 100 W, 220 V bulb.

________________________________________________________________________________

(v) Most thermistors have negative temperature coefficient of resistance.

________________________________________________________________________________

ALI RAZA KAMAL

ALI RAZA KAMAL




(i) Define electric current and its unit. Give value of current due to flow of 6 x 1018 electrons per second.

(ii) Explain direction of flow of current through any conductor or electrolyte.

(iii) Define conventional current and electrolysis. What are the charge carriers in Cu2SO4 solution?

(iv) Describe the effect of electric field E on the motion of free electrons.

(v) What are the sources of current? Explain briefly with examples.

(vi) State Ohm’s law. Explain its limitations. Differentiate between Ohmic and Non-Ohmic devices.

(vii) Define e.m.f. and describe its various types.

(viii) What is meant by:

(a) thermocouple

(b) electroplating

(c) electrolyte

(d) electrode

(e) voltmeter

(f) anode

(g) cathode

(h) resistance

(i) internal resistance

(j) substrate


(i) Define and write S.I. unit of

(a) conductivity

(b) conductance

(c) temperature coefficient of resistance

(d) temperature coefficient of resistivity

(ii) Define series and parallel combination of resistances.

(iii) Define resistivity and derive its expression. What is its S.I. unit? Give four examples.

(iv) Describe the effect of temperature on the resistivity of conductor.

(v) What are carbon resistors? Give the different bands of colour codes.

(vi) Define rheostat and its construction. Describe its working as:

(a) variable resistor

(b) potential divider

(vii) What are thermistors? Give some uses of thermistors.

(viii) Are there some substances whose resistance decreases with increase in temperature?


(i) Define electrical power. What is the S.I. unit of electrical power?

(ii) Why is an alkali cell said to be less efficient than an acid cell?

(iii) Differentiate between e.m.f of a battery and potential difference.

(iv) Derive the expression for maximum power output.

(v) Describe the relationship between the e.m.f of a battery and terminal potential difference. Explain this

relationship on the basis of energy consideration.

(vi) Define potentiometer, its construction and working. Describe its advantage over voltmeter.

ALI RAZA KAMAL

ALI RAZA KAMAL

(vii) Under what conditions an e.m.f can deliver maximum power to a resistor.

(viii) Which kinds of energy do convert

(a) thermo-couples

(b) solar cells

(c) electric generator

(d) cells


Q: 8 Attempt FOUR questions. (4 x 4 = 16)

1. State Kirchhoff’s Rules and explain them.

2. Explain Wheatstone bridge with the help of circuit diagram.

3. Give the heating, magnetic and chemical effects of the current.

4. Derive expressions for electrical power and power dissipations in resistors.

Q: 9 Attempt FOUR numerical. (4 x 1 = 4)

1. How many electrons pass through an electric bulb in 1 minute if 300 mA current is passing through it?

2. A charge of 90 C passes through a wire in 1 hour and 15 minutes. What is the current in the wire?

3. A rectangular bar of iron is 2.0 cm by 2.0 cm in cross section and 40 cm long. Calculate its resistance if

the resistivity of iron is 11 x 10-8 Ωm.

4. The resistance of an iron wire at 0 °C is 1 x 104 Ω. What is the resistance at 500 °C if temperature

coefficient of resistance of iron is 5.2 x 10-3 K-1?



A. Write down procedure to find the resistance of a voltmeter by drawing graph between R and 1/V.


(i) Define volt and the instrument used for measuring potential difference between two points.

(ii) Why voltmeter is always connected in parallel?

(iii) How galvanometer can be converted into voltmeter?

(iv) How can we increase the range of a voltmeter?

(v) Give some characteristics of good voltmeter.

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 14: ELECTROMAGNETISM

Physics Class: XII


Scheme (13)

Weightage = 10.5% MCQ’s = 2 Short Questions = 4 Extensive Question = 1(Numerical)



(i) Which of the following particles moving in magnetic field would not be deflected:

(a) α-particles (b) β-particles (c) electron (d) Neutron

(ii) The coil is situated in the magnetic field such that the plane of the coil is always:

(a) at 60° to field (b) at 45° to field (c) parallel to field (d) perpendicular to field

(iii) A device used for the detection of current is called:

(a) ammeter (b) voltmeter (c) galvanometer (d) ohmmeter

(iv) In order to increase the range of an ammeter, the shunt resistance is :

(a) made zero (b) increased (c) kept constant (d) decreased

(v) Ammeter is a __________ resistance instrument.

(a) zero (b) infinite (c) high (d) low

(vi) Which of the following apparatus is used to measure current, voltage and resistance:

(a) ohmmeter (b) ammeter (c) voltmeter (d) AVO meter


(i) A current carrying conductor is surrounded by ____________.

(ii) The charged particle moving in a magnetic field experiences a magnetic force given by __________.

(iii) The relation B = µoI/2πr is called ____________.

(iv) A galvanometer is converted into an ammeter by connecting a suitable ____________.

(v) The sensitivity of a galvanometer is given by ____________.

(vi) One tesla is equal to ____________ Gauss and ____________ NA-1m-1.


(i) Magnetic force on a moving charge is maximum when θ= 90°. ______

(ii) The charge moving perpendicular to B experiences no force. ______

(iii) Weber is unit of electric flux. ______

(iv) The magnetic force is restoring force. ______

(v) An electron of mass m and charge e moving in a circle of radius r with velocity v in a uniform

magnetic field of strength B, then r α m. ______

(vi) A device used for the detection of current is called ohmmeter. ______


(i) Resistance of an ammeter should be very low.

________________________________________________________________________________

(ii) Voltmeter should have a very high resistance.

________________________________________________________________________________

(iii) The picture on a TV screen becomes distorted when a magnet is brought near the screen.

________________________________________________________________________________

(iv) We can use a magnetic field to separate isotopes of chemical element.

________________________________________________________________________________

(v) We can use a current loop to determine the presence of a magnetic field in a given region of space.

________________________________________________________________________________

ALI RAZA KAMAL

ALI RAZA KAMAL




(i) Define

(a) magnetic field

(b) line of magnetic force

(c) right hand rule

(d) magnetic field strength

(e) flux density

(f) solenoid

(g) shunt resistance

(ii) Describe the properties of magnetic field due to current in a long straight conductor.

(iii) Write the factors upon which magnetic force depends.

(iv) How the presence of magnetic field is determined around a current carrying conductor

(v) What is magnetic flux? Describe its different cases.

(vi) What do you know about the Lorentz force?

(vii) Find out expression of torque on a current carrying coil.

(viii) What do you know about galvanometer? Give its working principle.

(ix) Elaborate the construction and working of galvanometer briefly.

(x) When do magnetic lines of force become clockwise and anti-clockwise?

(xi) An isolated magnet is not possible. How can we have it for some practical purpose?

(xii) Does electric current generate magnetic field?

(xiii) What is the force experienced by a current carrying rod placed in an external magnetic field? The rod

is placed parallel to the field.


(i) Define galvanometer and its types. What is meant by:

(a) tensional couple

(b) deflecting couple

(c) restoring couple

(ii) Define sensitivity of galvanometer. What is deadbeat galvanometer?

(iii) Define ammeter and its working principle.

(iv) Describe the working of an ammeter.

(v) Define ohmmeter and its working principle.

(vi) Describe the construction and working of ohmmeter.

(vii) What is C.R.O.? Give its construction.

(viii) Elaborate the working of Cathode Ray Oscilloscope and give its applications.

(ix) How poles of solenoid can be found? Why is B non-zero outside of a solenoid?

(x) Can an electron at rest be set in motion with a magnet?

(xi) Why a voltmeter is connected parallel to the points between which voltage is to be measured?

(xii) Why a voltmeter cannot read the exact end of a cell?

(xiii) Why an ammeter is connected in series with the circuit component?


Q: 7 Attempt FIVE questions. (5 x 2 = 10)

1. Derive the expression of force on a current carrying conductor in a uniform magnetic force.

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ALI RAZA KAMAL

2. Derive an expression to calculate the e/m value of an electron.

3. State the Ampere’s Law. Apply it to find out the magnetic field strength inside a current carrying solenoid.

4. (a) Find out the expression of magnetic force on a moving charge in a magnetic field.

(b) Find out expression of resistance that is connected in series with galvanometer to convert it into

voltmeter.

5. What is AVO meter? Write down the working of AVO meter in detail. Discuss digital multimeter.


1. Find the value of magnetic field that will cause a maximum force of 7.0 x 10-3 N on a 20.0 cm straight

wire carrying a current of 10.0 A.

2. A power line 10.0 m high carries a current 200 A. Find the magnetic field of the wire at the ground.

3. A coil of 0.1 m x 0.1 m and of 200 turns carrying a current of 1.0 mA is placed in uniform magnetic field

of 0.1 T. Calculate the maximum torque that acts on a coil.



A. Write down procedure to study the variation of magnetic field along the axis of a circular coil.


(i) Define magnetic field and flux density along with their units.

(ii) Define line of magnetic force. What is direction of magnetic lines of forces?

(iii) What is direction of field at the center of the coil and at the ends of current carrying coil?

(iv) Define strength of magnetic field.

(v) When current passing through two straight parallel closed wires in same direction attract or repel

each other?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 15: ELECTROMAGNETIC INDUCTION

Physics Class: XII


Scheme (15)




(i) A 50 mH coil carries a current of 2 A. the energy stored in its magnetic field is:

(a) 0.05 J (b) 10 J (c) 100 J (d) 0.1 J

(ii) The motional e.m.f developed in a conductor depends upon:

(a) length (b) orientation (c) magnetic field (d) all of these

(iii) The negative sign with induced e.m.f in Faraday’s law is in accordance with :

(a) Coulomb’s law (b) Ampere’s law (c) Gauss’s law (d) Lenz’s law

(iv) The self inductance is expressed by the relation L=

(a) ∆ф/∆t (b) ∆I/∆t/ ε (c) εx∆I/∆t (d) ε /∆I/∆t

(v) The energy stored in an inductor is given by :

(a) 2L/I2 (b) L/2I2 (c) LI2 (d) LI2/2

(vi) A device consisting of two coils wound on an iron core is called:

(a) electric motor (b) A.C. generator (c) D.C. generator (d) transformer


(i) The current flowing through a coil due to induced e.m.f in it depends upon____________.

(ii) The energy stored in an inductor is given by ____________.

(iii) When a coil is moved in a uniform magnetic field, an induced e.m.f is produced due to change of

____________.

(iv) Mutual inductance of coil depends upon ____________.

(v) One Henry is equal to ____________ VsA-1.

(vi) A.C. can be measured with the help of ____________ effect.


(i) Henry is the unit of self-inductance only. ______

(ii) A rectifier converts an alternating current into direct current. ______

(iii) A transformer consists of an iron core with a primary coil and a secondary coil. ______

(iv) A transformer works on the principle of Faraday’s law. ______

(v) The principle of A.C. generator is electromagnetic induction. ______

(vi) Eddy currents are produced in a material when it is placed in time varying electric field. ______


(i) D.C. motor can be turned into a D.C. generator.

________________________________________________________________________________

(ii) The induced e.m.f does not always act to decrease the magnetic flux through a circuit.

________________________________________________________________________________

(iii) The inducted e.m.f in circuit does not depend on the resistance of the circuit.

________________________________________________________________________________

(iv) The induced current in circuit depends on the resistance of the circuit.

________________________________________________________________________________

(v) Step-up transformer cannot increase the power level.

________________________________________________________________________________

ALI RAZA KAMAL

ALI RAZA KAMAL




(i) Define and give S.I. unit of

(a) electromagnetic induction

(b) induced e.m.f.

(c) induced current

(d) motional e.m.f.

(e) Faraday’s law

(f) Lenz’s law

(g) mutual induction

(h) self inductance.

(ii) What is alternating current generator? Describe its working principle and construction.

(iii) Elaborate working of A.C. generator.

(iv) Write a brief note on D.C. generator.

(v) Describe the back e.m.f. effects in generators.

(vi) Write a brief note on D.C. motor.

(vii) What do you know about back e.m.f. effects in motors?

(viii) Describe the relation between back e.m.f and current.

(ix) Is the law of conservation of energy applicable to the phenomena of induction?

(x) Name the factors on which mutual induction and self-inductance depend.

(xi) Can energy be store in magnetic field of inductor?

(xii) May an inductor coil appear like a solenoid?


(i) Can inductors be used in capacitor?

(ii) What happened when any motor is over loaded?

(iii) Does the voltage output of a generator change if its speed of rotation is increased?

(iv) What is transformer? Describe its principle and construction.

(v) Explain the working of transformer. Does transformer obey the law of conservation of power?

(vi) Differentiate between step-up transformer and step-down transformer.

(vii) What is the difference between an ideal transformer and an actual transformer?

(viii) Describe the different causes of power loss.

(ix) Define

(a) eddy current

(b) hysteresis

(c) inductor

(d) energy density

(e) generator

(f) load in an electrical circuit

(g) commutator.

(x) Define efficiency of a transformer. How can we improve the efficiency of the transformer?

(xi) Show that Ɛ and ∆Φ

∆t have the same units.

(xii) Four unmarked wires emerge from a transformer. What steps would you take to determine the turn

ratio?

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ALI RAZA KAMAL



1. Define the term motional e.m.f. Also, derive its expression.

2. State and prove the Faraday’s law of electromagnetic induction.

3. State and explain the Lenz’s law. Describe Lenz’s law as a statement of law of conservation of energy.

4. Differentiate between mutual induction and self-induction Derive their expressions.

5. Find out the expression of energy stored in the magnetic field of current carrying inductor.


1. A circular coil has 15 turns of radius 2 cm each. The plane of the coil lies at 40° to a uniform magnetic

field of 0.2 T. If the field is increased by 0.5 T in 0.2 s, find the magnitude of the induced e.m.f.

2. A square coil of side 16 cm has 200 turns and rotates in a uniform magnetic field of magnitude 0.05 T.

If the peak e.m.f. is 12 V, what is the angular velocity of the coil?

3. An ideal step down transformer is connected to main supply of 240 V. It is desired to operate a 12 V,

30 W lamp. Find the current in the primary and the transformation ratio.



A. Write down procedure to study the characteristics of a semi-conductor diode.


(i) What are semi conductors? Differentiate it with conductor.

(ii) Define forward and reverse bias.

(iii) Define semi-conductor diode. Give its uses.

(iv) Define PN junction.

(v) Define hole and electrons.

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 16: ALTERNATING CURRENT

Physics Class: XII


Scheme (13)

Weightage = 10.5% MCQ’s = 2 Short Questions = 3 Extensive Question = 1(Theory)



(i) If the peak value of A.C. voltage is 10√2 , then its root mean square value will be:

(a) 5 volts (b) 20 volts (c) 25 volts (d) 10 volts

(ii) The power dissipated in a pure inductive or capacitive circuit is:

(a) zero (b) minimum (c) moderate (d) maximum

(iii) Impedance is composed of:

(a) R (b) R and C (c) R and L (d) R, L and C

(iv) The frequency of A.C. used in Pakistan is _____ CPS (Hz).

(a) 50 (b) 60 (c) 100 (d) 120

(v) The highest value reached by voltage or current in one cycle is called _______ value.

(a) Peak to peak (b) Peak (c) Instantaneous (d) Root mean square

(vi) At high frequency RLC, series circuit shows the behavior of _______ circuit. circuit

(a) pure resistive (b) pure capacitive (c) pure inductive (d) pure RLC


(i) The most common source of alternating current is ____________.

(ii) The root mean square value of the current is given as ____________.

(iii) The opposition offered by the inductor to the flow of A.C. is called ____________.

(iv) Resonance frequency of parallel resonance circuit is fr= ____________.

(v) A changing magnetic field creates ____________ field.

(vi) A changing electric flux creates a ____________ field.


(i) The current, which changes its direction through the circuit for a complete cycle, is called alternating

current. ______

(ii) In case of capacitor, S.I. unit of reactance is farad. ______

(iii) S.I. unit of impedance is ohm. ______

(iv) James Clark Maxwell discovered Maxwell’s equations in 1864. ______

(v) A sinusoidal current has rms value of 10 A. Its maximum value is 7.77 A. ______

(vi) If Vrms=10√2 then peak voltage V0 is 10 V. ______


(i) The reception of a particular radio station is selected by tuning on your radio set.

________________________________________________________________________________

(ii) Electromagnetic waves are produced from a source.

________________________________________________________________________________

(iii) A choke coil placed in series with an electric lamp in an AC circuit causes the lamp to become dim.

________________________________________________________________________________

(iv) In a RL circuit, the current will leads the voltage.

________________________________________________________________________________

(v) A sinusoidal current has rms value of 10 A. It is the maximum value of the current.

________________________________________________________________________________

ALI RAZA KAMAL

ALI RAZA KAMAL




(i) Define alternating current. Why alternating current keeps on changing its direction with time?

(ii) Define following for an alternating quantity:

(a) Instantaneous value

(b) Peak Value

(c) Peak to Peak Value

(d) Phase of AC

(iii) What do you mean by Root Mean Square (rms) value of an alternating quantity? Describe its

significance. Derive an expression to calculate the rms value of an alternating quantity.

(iv) Define time period and frequency of an alternating voltage.

(v) Differentiate between A.C. and D.C. Give the basic controlling element of both.

(vi) Why D.C. cannot flow through a capacitor?

(vii) Define A.C. circuits. Describe the power dissipation in A.C. circuits.

(viii) Define reactance and its unit. Differentiate between capacitive reactance and inductive reactance.

(ix) Define the term impedance and choke.


(i) Differentiate between series resonance circuit and parallel resonance circuit.

(ii) Define power. What is the relation of power in an A.C. circuit?

(iii) Give any four properties of series resonance circuit and parallel resonance circuit.

(iv) Define the term modulation. Describe its different types.

(v) Describe the basic principle of metal detectors.

(vi) Write a note on three-phase A.C. supply.

(vii) What are electromagnetic waves? Give its wavelength and different types.

(viii) What is principle for generation of electromagnetic waves?

(ix) How voltage and current behave in a pure resistive circuit?



1. Describe the relationship between instantaneous voltage and current when AC passes through

resistor.


capacitor.


inductor.

4. What is meant by following circuits? Calculate their impedance by drawing their impedance diagram.

(a) RC Series Circuit (b) RL Series Circuit

5. Find out expression for resonance frequency for the case of series resonance circuit.

Q: 8 Attempt SIX numerical. (6 x 2 = 12)

1. An alternating current is represented by the equation I = 20 sin 100 πt. Compute its frequency and the

maximum and rms values of current.

2. Find the value of the current and inductive reactance when A.C. voltage of 220 V at 50 Hz is passed

through an inductor of 10 H.

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ALI RAZA KAMAL

3. A circuit has an inductance of 1/π H and resistance of 2000 Ω. A 50 Hz A.C. is supplied to it. Calculate

the reactance and impedance offered by the circuit.

4. A 10 mH, 20 Ω coil is connected across 240 V and 180/π Hz source. How much power does it dissipate?

5. Find value of current flowing through a capacitance 0.5 µF when connected to source of 150 V at 50 Hz.

6. What is resonant frequency of circuit, which includes a coil of inductance 2.5 H and capacitance 40 µF?



A. Write down procedure to study the characteristics of an N-P-N transistor.


(i) Give types and uses of transistors.

(ii) How many PN junctions are there in a transistor?

(iii) What are the conditions for a transistor to conduct?

(iv) What are advantages of transistors?

(v) How the transistors are used in electrical circuits?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 17: PHYSICS OF SOLIDS

Physics Class: XII


Scheme (10)




(i) The ratio of applied stress to volumetric strain is called:

(a) Bulk modulus (b) Shear modulus (c) Tensile modulus (d) Young’s modulus

(ii) An n-type semiconductor is formed by adding impurity:

(a) aluminium (b) gallium (c) phosphorous (d) All of these

(iii) A hole in a p-type material is:

(a) missing proton (b) excess electron (c) missing atom (d) missing electron

(iv) Magnetism lags behind the magnetizing current this phenomenon is called:

(a) Hysteresis (b) Saturation (c) Retaintivity (d) None

(v) The substances with conductivies between 10-10 and 10-20 (Ω m)-1 are called:

(a) conductors (b) insulators (c) superconductors (d) semiconductors

(vi) Acceptor impurities are:

(a) phosphorous (b) germanium (c) silicon (d) aluminium


(i) A solid having regular arrangement of molecules throughout its structure is called ____________.

(ii) The ability of a body to return to its original shape is called ____________.

(iii) The value of stress beyond which a body is permanently deformed is called ____________.

(iv) A vacant or partially filled band is called ____________.

(v) The materials whose resistivity becomes zero below a certain temperature are called ____________.

(vi) The value of resistivity of semiconductors is of the order of ____________ Ω m.


(i) Substances, which break just after elastic limit is reached, are called soft substances. ______

(ii) A completely filled band is called conduction band. ______

(iii) The first superconductor was discovered in 1990. ______

(iv) The critical temperature for mercury is 7.2 K. ______

(v) The doped semiconductors are called extrinsic semiconductor. ______

(vi) N-type germanium is obtained by doping intrinsic germanium with tetravalent impurity atom. ______


(i) The pattern of NaCl particles has a cube shape.

________________________________________________________________________________

(ii) There are seven different crystal systems based on the geometrical arrangement of their atoms and

the resultant geometrical structures.

________________________________________________________________________________

(iii) Glass is also known as solid liquid.

________________________________________________________________________________

(iv) Magnetic Resonance Imaging (MRI) uses strong magnetic field.

________________________________________________________________________________

(v) Curie temperature of iron is about 750 °C.

________________________________________________________________________________

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ALI RAZA KAMAL




(i) Define crystalline solids. Describe their properties.

(ii) What are amorphous or glassy solids? Give their properties.

(iii) What are polymeric solids? Elaborate their properties.

(iv) Define following:

(a) Unit Cell

(b) Crystal Lattice

(v) What is deformation? Describe the phenomenon of deformation in crystalline solids.

(vi) What are mechanical properties of solids?

(vii) Define the term stress. Describe its different types.

(viii) Define the term strain. Elaborate its different types.

(ix) Define Modulus of Elasticity. Describe its different types.

(x) Define

(a) Proportional Limit

(b) Yield Stress/Elastic Limit

(c) Ultimate Tensile Stress (UTS)


(i) Classify the solids on the basis of plastic deformation of solids.

(ii) Define strain energy.

(iii) Briefly describe electrical properties of solids.

(iv) What is energy band theory of solids?

(v) Define :

(a) Energy Band

(b) Forbidden Band

(c) Valance Band

(d) Conduction Band

(vi) Describe the variation in conductivity of semi-conductors due to effect of temperature.

(vii) Differentiate among intrinsic and extrinsic semi-conductor materials.

(viii) Define the crystal structure of intrinsic semi-conductors.

(ix) Describe the different types of extrinsic semi-conducting materials.

(x) What do you meant by:

(a) Conductors

(b) Insulators

(c) Semi-conductors

(d) Doping


(i) What is effect of battery on the motion of charge carrier in a semi-conductor crystal?

(ii) Define:

(a) Superconductors

(b) Critical Temperature

(c) High Temperature Superconductors

(iii) Describe the applications of superconductors.

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(iv) What is the reason of magnetic behavior of solids?

(v) Differentiate among the paramagnetic and diamagnetic substances.

(vi) What do you know about the Curie temperature in Ferromagnetic Substances?

(vii) How the Hysteresis Loop of a magnetic material is obtained?

(viii) Describe the advantages of Hysteresis Loop.

(ix) Define the following properties of Hysteresis Loop:

(a) Hysteresis

(b) Saturation

(c) Remanence or Retaintivity

(d) Coercivity

(e) Area of Hysteresis Loop

(x) Write a note on ferromagnetic substances. Also, describe its different types.


Q: 8 Attempt THREE questions. (3 x 2 = 6)

1. How the mechanical properties of a wire are determined in tensile test?

2. Define strain energy. Also, derive expression of strain energy by considering force-elongation graph

obtained during the tensile test of a wire.

3. Differentiate among conductors, insulators and semi-conductors on the basis of band theory of solids.

Q: 9 Attempt TWO numerical. (2 x 1 = 2)

1. A 1.25 cm diameter cylinder is subjected to a load of 2500 kg. Calculate the stress on the bar in MPa.

2. A 1.0 m long copper wire is subjected to stretching force and its length increases by 20 cm. Calculate the

tensile strain and the percent elongation, which the wire undergoes.



A. Write down procedure to study the variation of electric current with intensity of light using a photocell.


(i) Define light

(ii) State law of conversion of energy.

(iii) What is photoelectric cell?

(iv) What is photocell?

(v) What are uses of photocell?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 18: ELECTRONICS

Physics Class: XII


Scheme (11)




(i) Depletion region carries:

(a) negative charge (b) positive charge (c) protons (d) no charge

(ii) Photo diode can turn its current on and off in:

(a) nano sec (b) micro sec (c) milli sec (d) sec

(iii) The circuit which changes input signal at the output with a phase shift of 180° is called:

(a) diode (b) switch (c) inductor (d) Inverter

(iv) A NAND gate with two inputs A &B has an output 0, if:

(a) A =0 (b) B =0 (c) Both A & B are 0 (d) Both A & B are 1

(v) The automatic working of street lights is due to:

(a) inductor (b) capacitor (c) comparator (d) rectifier

(vi) A photo diode is used for:

(a) logic circuits (b) automatic switching (c) photo detection (d) all of these


(i) The current gain ratio β of a transistor is given as ____________.

(ii) The gain of the non-inverting amplifier can be expressed as ____________.

(iii) When a p-n junction is reverse biased, the depletion region is widened ____________.

(iv) The equation of voltage gain β of an amplifier can be expressed as ____________.

(v) The magnitude of open loop gain of the operational amplifier is of the order of ____________.

(vi) Base of the transistor is very thin of the order of ____________.


(i) Transistors are made from plastics. ______

(ii) In reverse biasing, a p-n junction offers high resistance. ______

(iii) The potential difference set up across the depletion region is called absolute potential. ______

(iv) The diode cannot be used as rectifier. ______

(v) The electronic circuit, which gives the inversion of input signal at the output, is called AND gate.

______

(vi) The central region of a transistor is called emitter. ______


(i) Ordinary silicon diodes do not emit light.

________________________________________________________________________________

(ii) A photo diode is operated in reverse biased state.

________________________________________________________________________________

(iii) The base current in a transistor is very small.

________________________________________________________________________________

(iv) Charge carriers are not present in the depletion region.

________________________________________________________________________________

(v) For normal operation, the base emitter junction is forward biased.

________________________________________________________________________________

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ALI RAZA KAMAL




(i) What is electronics?

(ii) Define following:

(a) p-type substance

(b) n-type substance

(c) depletion region

(d) potential barrier

(iii) What is a p-n junction? When a p-n junction is formed?

(iv) What is the net charge on the n-type and p- type substance?

(v) Define biasing. What do you mean by forward biasing and reverse biasing?

(vi) What is the unit of potential hill or potential barrier? Write potential barrier of germanium and silicon.

(vii) Give the symbolic representation of p-n junction. Define forward resistance of the p-n junction.

(viii) What is the effect of forward and reverse biasing of a diode on the width of depletion region?


(i) What is rectification? Give its types and essential components required.

(ii) How many diodes may be used for half wave rectification and full wave rectification?

(iii) Write down some special kinds of diodes. What is the use of a photo diode?

(iv) What is difference between a half wave rectification and full wave rectification?

(v) What do you mean by:

(a) photovoltaic cell

(b) transistor

(c) n-p-n transistor

(d) p-n-p transistor

(vi) What type of energy transfer is related to a photo voltaic cell?

(vii) Draw a circuit symbol of

(a) n-p-n transistor

(b) p-n-p transistor

(c) operational amplifier

(viii) What is the voltage gain of a transistor? In addition, what is the current gain of a transistor?


(i) Define:

(a) output resistance

(b) input resistance

(c) amplifier

(d) operational amplifier.

(ii) Define saturation in operational amplifier. Write some important uses of operational amplifier.

(iii) How operational amplifier acts as a comparator?

(iv) What is meant by:

(a) LDR

(b) logic gate

(c) AND gate

(d) OR gate

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ALI RAZA KAMAL

(e) NOT gate

(f) NAND gate

(g) NOR gate

(h) exclusive OR gate, XOR

(i) exclusive NOR gate XNOR.

(v) Write the equation of a gain of an inverting amplifier and non-inverting-amplifier.

(vi) What is Boolean algebra? What is the function of a sensor?


Q: 8 Attempt FOUR questions. (4 x 4.5 = 18)

1. Define rectification. Elaborate its types in detail.

2. Give a brief note on specially designed p-n junction explaining

(a) light emitting diode

(b) photo diode

(c) photo-voltaic cell

3. Define operational amplifier. Give its characteristics.

4. Give an expressions of

(a) op-amp as inverting amplifier

(b) op-amp as non-inverting amplifier

(c) op-amp as a comparator

(d) comparator as a night switch


1. The current flowing into the base of a transistor s 100 µA. Find its collector current IC, its emitter current

IE and the ratio IC/IE, if the value of current gain β is 100.

2. Find the gain of the inverting amplifier external resistance R1 =100 kΩ and R2 = 400 kΩ.

3. Find current gain p of a transistor whose collector current is 50 mA and base current is 50 mA.



A. Write down procedure to verify the truth table for logic gates.


(i) What are logic gates? Give its uses.

(ii) Define truth table. Give the truth tables for logic gates.

(iii) Define AND, OR, NOT, NAND and NOR gate.

(iv) What are characteristics of AND, OR, NOT, NAND and NOR gate?

(v) How many outputs must be provided to AND and OR gate? What the NOT gate so called?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 19: DAWN OF MODERN PHYSICS

Physics Class: XII


Scheme (12)




(i) In photoelectric effect, light exhibits:

(a) wave-nature (b) particle nature (c) both a & b (d) all of these

(ii) Absorption power of a perfect black body is:

(a) 0 (b) 0.5 (c) infinity (d) 1

(iii) All motions are:

(a) absolute (b) uniform (c) variable (d) relative

(iv) The total energy radiated / unit orifice area of cavity radiator / unit time is directly proportional to:

(a) T (b) T2 (c) T3 (d) T4

(v) The pair production and annihilation of matter are __________ phenomenon.

(a) Similar (b) Opposite (c) both a & b (d) all of these

(vi) Mathematical treatment for electromagnetic waves was given by:

(a) Faraday (b) Hertz (c) Coulomb (d) Maxwell


(i) Max Planck awarded the Nobel Prize in ______, Arthur Holly Compton in ______, de-Broglie in

______, Davisson in ______, Germer in ______ and Albert Einstein in ______.

(ii) The nature of light confirmed by photoelectric effect is ____________.

(iii) The amount of energy needed to carry out phenomenon of pair production is ____________.

(iv) The special theory of relativity was proposed in ____________.

(v) The earth is a frame of reference of type ____________.

(vi) The length contraction happens in the direction ____________.


(i) 0.1 kg will be equivalent to the energy 6 x 1016 joules. ______

(ii) A non-inertial frame of reference is that one which is accelerated. ______

(iii) Einstein’s photoelectric equation is given by mv2max / 2 = hf + ф. ______

(iv) The de-Broglie wavelength of a particle is proportional to its momentum. ______

(v) The SI unit of Planck’s constant is J s. ______

(vi) Emission of electron by metals on heating is called secondary emission. ______


(i) Air is named as free space.

________________________________________________________________________________

(ii) The length of a spacecraft may vanish if it moves with the speed of light.

________________________________________________________________________________

(iii) Velocity of light is the greatest possible velocity for material bodies.

________________________________________________________________________________

(iv) Can the length contraction be observed perpendicular to the direction of motion?

________________________________________________________________________________

(v) Can the phenomenon of black body radiation be explained by classical physics?

________________________________________________________________________________

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ALI RAZA KAMAL




(i) Define:

(a) relative motion

(b) rest and motion

(c) frame of reference

(d) inertial frame of reference

(e) non-inertial frame of reference

(f) modern physics

(g) special theory of relativity

(h) photocell

(ii) What are basic postulates of special theory of relativity? Which one of these is more important?

(iii) What are the important results concluded by Einstein? Is the mass of an object a varying quantity?

(iv) Is time an absolute quantity according to special theory of relativity?

(v) What do you mean by:

(a) black body

(b) radiation

(c) absorption power of a black body

(d) photons

(e) quanta

(f) photoelectric effect

(g) photoelectrons

(h) photoelectric current

(i) cut off or stopping potential

(vi) What is the relation for relativistic mass and relativistic length?

(vii) What is the mass ‘m’ of an object moving with speed 0.6 V?

(viii) What is meant by

(a) positron

(b) annihilation of matter

(c) particle duality

(d) electron microscope

(ix) Define pair production. What laws should be conserved during the phenomenon of pair production?

What was the outcome of phenomenon of pair production?

(x) State Stephen-Boltzmann Law. What is the value of Stephens constant?


(i) How the temperature affects the wavelength of the radiations emitted by a black body?

(ii) Give the Max Planck’s explanation of the radiation emitted by a black body.

(iii) Is the energy ‘E’ of each quanta proportional to its frequency T?

(iv) What is a relation for the momentum of photon is term of frequency and in term of wavelength?

(v) Would it be more convenient to demonstrate photoelectric effect with ultra-violet light or visible light?

(vi) If E and P are the energy and momentum of a photon, calculate the velocity of light.

(vii) What is threshold frequency for a metal? Does it vary from metal to metal?

(viii) What is the colour of a black body, which emits all the wavelengths in the visible spectrum of

electromagnetic waves? Is a black body an ideal absorber or an ideal radiator?

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ALI RAZA KAMAL

(ix) What is meant by:

(a) general theory of relativity

(b) law of inertia

(c) speed of light in free space

(d) relativistic time

(e) rest mass energy

(f) Einstein’s energy mass relation

(g) work function

(x) State Heisenberg uncertainty principle. How uncertainty principle between energy and time is

related?


(i) Write some important factors upon which photoelectron effect depends.

(ii) Write the Einstein’s photoelectric equation. Write some important results of the photoelectric effect.

(iii) Write some important characteristics of photon and the relation for maximum K.E. of photoelectron.

(iv) Are the electrons emitted with different energies in photoelectric effect?

(v) What phenomena may occur when electromagnetic waves interact with the matter?

(vi) Write some important uses of photocells and de-Broiler’s wavelength associated to atomic particle.

(vii) State Compton Effect. Write the Compton equation, showing the frequency of scattered photon.

(viii) What aspect of light Compton scattering experiment can verify?

(ix) What is Compton shift and Compton wavelength? When are both of these equal?


Q: 8 Attempt TWO questions. (2 x 2 = 4)

1. Explain the wave nature of particles. Derive its expression.

2. Elaborate special theory of relativity with reference to time dilation and length contraction.

Q: 9 Attempt SIX numerical. (6 x 1 = 6)

1. Light of wavelength 1240 nm is incident on a metallic surface. What is the energy of incident photons?

2. The cut off voltage for a certain metal is 10 volts. Find the work function for the cathode plate.

3. What is the Compton shift in the wavelength of a photon scattered at an angle 90°?

4. Calculate de-Broglie wavelength

(a) A particle of mass 6.0 mg moves with speed of 8.0 MeV.

(b) An electron is accelerated through a potential difference of 50 V.

5. An electron is placed in box about size of atom that is about 1.0 x 10-10 m. What is the velocity of

electron?

6. The lifetime of the electron in excited state is about 10-8 s. What is its uncertainty in energy during this

time?



A. Write down procedure to make burglar alarm using NAND gate.


(i) What is meaning of logic 1 and 0?

(ii) Define logic gates and give its uses.

(iii) What is inverter gate?

(iv) Define truth table. Give the truth tables for logic gates.

(v) What are characteristics of logic gates?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 20: ATOMIC SPECTRA

Physics Class: XII


Scheme (9)




(i) In the state n=∞ of hydrogen atom, total energy of electron is:

(a) 10.5 eV (b) 9.8 eV (c) 5.2 eV (d) zero

(ii) In 1913, modern tube for production of X-rays was designed by:

(a) Planck (b) Einstein (c) Roentgen (d) Dr. W. Coolidge

(iii) k-series of characteristic X-rays are produced when all the transitions of inner-shell electrons

terminate on:

(a) M-shell (b) L-shell (c) N-shell (d) K-shell

(iv) Wavelength shorter than violet is called:

(a) x-rays (b) γ-rays (c) infra red radiation (d) ultra violet radiation

(v) The residing time of atoms in meta stable state in case of laser action is:

(a) 10-5 sec (b) 10-5 sec (c) 10-8 sec (d) 10-3 sec

(vi) The potential required to remove an electron from the atom is called:

(a) critical potential (b) ionization potential (c) excitation potential (d) absolute potential


(i) The value of Rydberg’s constant is ____________ and that of Planck’s constant is ____________.

(ii) The net force on an electron in an orbit revolving around the nucleus is ____________.

(iii) There are ____________ electronic orbits in a hydrogen atom.

(iv) The value of radius of first Bohr orbit is ____________ and that of third is ____________.

(v) The energy of electron of hydrogen atom in the first orbit (ground state) is ____________.

(vi) The ordinary lifetime of an electron in the excited slate is ____________.


(i) The simplest spectrum is that of oxygen. ______

(ii) X-rays are affected by electric and magnetic field both. ______

(iii) The energy of the 4th orbit in hydrogen atom is -0.85 eV. ______

(iv) If an electron jumps from lower to higher orbit it will emit energy. ______

(v) The radiations emitted from hydrogen filled discharge tube shows line spectrum. ______

(vi) The Balmer series is obtained when all the transitions of electron terminate on 4th orbit. ______


(i) The energy of an electron while revolving in a stationary orbit is negative.

________________________________________________________________________________

(ii) The hydrogen atom contains only a single electron yet the hydrogen spectrum contains many lines.

________________________________________________________________________________

(iii) The electromagnetic wave energy emitted in space by a point source obeys inverse square law.

________________________________________________________________________________

(iv) LASER action could not occur without population inversion between atomic levels.

________________________________________________________________________________

(v) Kinetic energy of x-rays photon can be found.

________________________________________________________________________________

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ALI RAZA KAMAL




(i) Define:

(a) spectroscopy

(b) spectrum

(c) atomic spectrum

(d) continuous spectrum

(e) band spectrum

(f) line spectrum

(g) ground state

(h) excited state

(i) ionization energy

(j) excitation energy

(ii) Name the types of spectra. List the possible series found in the spectrum of hydrogen atom.

(iii) Is black body radiation spectrum, continuous spectra?

(iv) Are molecular spectra the example of band spectra?

(v) In which region following series lies:

(a) Lyman series

(b) Paschen series

(c) Bracket series

(d) Pfund series

(e) Balmer series

(vi) Are atomic spectra the examples of discrete or line spectra?

(vii) When and who, propose a model of hydrogen atom?

(viii) What do you mean by a stationary orbit as postulated by Bohr?

(ix) List the colour of line spectra of an excited hydrogen atom


(i) Balmer series of hydrogen torn is photographed in the form of a number of lines whose wavelength

increase from left to right or extreme left line will be the brightest?

(ii) When was Balmer series of wavelengths of hydrogen atom identified?

(iii) Write down the Bohr’s radii of different stationary quantized orbits.

(iv) When an atom is said to be ionized? When an atom is said to be excited?

(v) What is meant by:

(a) x-rays

(b) cat-scanner

(c) LASER

(d) types of LASER

(e) meta-stable state

(f) stimulated emission

(g) helium-neon laser

(h) infra-red radiations

(vi) When and who discovered x-rays? Also, give its four uses.

(vii) Write any four properties of x-rays.

(viii) What is the value of I.E. of hydrogen atom?

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ALI RAZA KAMAL

(ix) What is the total energy of an electron of hydrogen atom?


(i) Find the speed of an electron in the first Bohr orbit.

(ii) What are the characteristics of x-rays?

(iii) What is wavelength range of x-rays?

(iv) Do the energies of characteristic x-rays depend upon the type of target material?

(v) What is difference between characteristic x- rays and continuous x-rays?

(vi) Which laser is most commonly used? Write some important uses of laser.

(vii) What is uncertainty with the atom regarding to position of electrons?

(viii) Can an electron reside inside the atom?

(ix) Why does laser usually emit only one particular colours of light rather than several colours?


Q: 8 Attempt THREE questions. (3 x 4 = 12)

1. Explain the uncertainty within the atom.

2. State postulates of Bohr’s model of hydrogen atom.

3. Derive an expression for quantized radii and quantized energies for an electron in nth orbit.

Q: 9 Attempt FOUR numerical. (4 x 2 = 8)

1. What are the energies in eV of quanta of wavelength? λ = 400, 500 and 700 nm.

2. An electron jumps from Ei = -3.56 x 10-19 J to Ef = -1.20 x 10-18 J. Calculate emitted light’s wavelength.

3. Compute the shortest wavelength radiation in Balmer series and Paschen series.

4. Find the wavelength of the spectral line corresponding to the transition in hydrogen from n=6 to n=3 state.



A. Write down procedure to make a fire alarm using gates.


(i) What is logic circuit?

(ii) What is binary circuit? Give its uses.

(iii) What is inverter gate?

(iv) Define AND, OR, NOT, NAND and NOR gate.

(v) What are characteristics of logic gates?

ALI RAZA KAMAL

ALI RAZA KAMAL

CHAPTER 21: NUCLEAR PHYSICS

Physics Class: XII


Scheme (15)




(i) Rutherford bombarded a thin sheet of gold with:

(a) γ-rays (b) β-particles (c) X-rays (d) α-particles

(ii) Which one of the following is not affected by the electric or magnetic field:

(a) α-particles (b) β-particles (c) protons (d) γ-rays

(iii) The most useful tracer is:

(a) Cobalt-60 (b) Nickel-63 (c) Cesium-137 (d) Carbon-14

(iv) After two half lives, the number of decayed nuclei of an element are:

(a) N (b) N/2 (c) 3N/4 (d) N/4

(v) A pair of quark and anti-quark makes a:

(a) baryon (b) photon (c) proton (d) meson

(vi) Gamma rays are emitted by de-excitation of:

(a) atom (b) molecule (c) element (d) nucleus


(i) Nuclei of different elements are identified by ____________.

(ii) For an atom having atomic number ‘Z’ and atomic mass ‘A’ the number of neutrons in the nucleus is

N = ____________.

(iii) The mass of positron is same as that of ____________.

(iv) Materials can be identified by measuring their ____________.

(v) The beta particles have ____________ path.

(vi) Thyroid glands play major role in distribution of ____________.


(i) Moderators slow down the neutrons. ______

(ii) Dr. Abdus Salam unified electromagnetic force and strong nuclear force. ______

(iii) Wilson cloud chamber is an instrument used for accelerating positively charged particle. ______

(iv) The binding energy per nucleon is greatest for medium weight nuclei. ______

(v) The atomic bomb is an example of controlled fission chain reaction. ______

(vi) Capture of a neutron by a nucleus results in the formation of triton. ______


(i) Heavy nuclei are unstable.

________________________________________________________________________________

(ii) A particle, which produces more ionization, is less penetrating.

________________________________________________________________________________

(iii) If a nucleus has a half-life of 1 year, it does not mean that it will completely decay after two years.

________________________________________________________________________________

(iv) Geiger Muller Tube for detecting α-particles must have a very thin end window.

________________________________________________________________________________

(v) Geiger Muller Tube for detecting γ-rays does not need a window at all.

________________________________________________________________________________

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ALI RAZA KAMAL




(i) Define:

(a) nuclear physics

(b) atomic number

(c) mass number

(d) isotopes

(e) binding energy

(ii) How much mass may be concentrated in the nucleus of atom?

(iii) What is the size of an atom and nucleus? How much is a nucleon heavier than electron?

(iv) What is the mass of an

(a) electron

(b) proton

(c) neutron in unified mass scale

(v) How the nucleus of an atom is represented?

(vi) Find the charge number, mass number and number of neutron in the nucleus of U-238.

(vii) Define and tell who discovered

(a) nucleus

(b) nucleons

(c) electron

(d) proton

(e) neutron

(f) positron

(g) anti-proton

(h) natural radioactivity

(viii) Who found out the charge on an electron? Name the element having maximum binding energy.


(i) What is meant by:

(a) stable nuclei

(b) radioactivity

(c) mass-energy equation

(d) radioactive decay

(e) daughter element

(f) α-decay

(g) β-decay

(h) γ-ray

(i) γ-decay

(j) transuranic elements

(ii) Which particle can be added to the nucleus without affecting its chemical properties?

(iii) How the binding energy of a nucleus and binding energy per nucleus can be determined?

(iv) Which elements are naturally occurring radioactive?

(v) What part of radioactive atom disintegrates during radioactivity?

(vi) Define decay constant. What is the unit of decay constant?

(vii) Define half-life of a radioactive element. Give its mathematical relation and two examples.

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ALI RAZA KAMAL

(viii) Give two properties of

(a) α-particles

(b) β-particles

(c) γ-ray

(d) neutrons when they interact with the matter


(i) What are radiation detectors? Give its different types.

(ii) Who invented cloud chamber? What is the principle of a cloud chamber?

(iii) Name the principal gas used in the G.M. counter. What is the drawback of a G.M. counter?

(iv) What is the basic structure of a solid-state detector?

(v) Name the subatomic particles. Define following:

(a) leptons

(b) barons

(c) hadrons

(d) mesons

(e) quarks

(vi) At present, how many forces exist in nature?



1. Explain the nuclear fission reaction.

2. Elaborate a comprehensive note on nuclear fusion reaction.

3. Explain the radiation detectors.

4. Differentiate between α-particles, β-particles and γ-radiations.

5. Define mass defect and binding energy. Derive their expressions.

Q: 9 Attempt FIVE numerical. (5 x 2 = 10)

1. Find the mass defect and the binding energy for tritium, if the atomic mass of tritium is 0.3016049 u.

2. The half-life of Sr3891 is 9.70 hours. Find its decay constant.

3. If U92233 decays twice by α-emission, what is the resulting isotope?

4. Determine the energy associated with the reaction:

C614

→ N714

+ e-10

5. Determine the energy (in MeV) released in the fusion reaction:

H12

+ H13

→ He24

+ n01



A. Write down procedure to study the characteristics of G-M (Geiger-Muller) Tube.


(i) Name the two types of Geiger counters. Which of these two is more sensitive and why?

(ii) Define Geiger Threshold and Geiger Plateau.

(iii) Define

(a) scalar

(b) background effect

(c) self-quenching counter

(iv) What do you mean by the characteristic curve of a counter?

(v) Define quenching of the discharge. How this quenching is achieved in practice?

ALI RAZA KAMAL

ALI RAZA KAMAL

2015-16 -...

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