btce24,btme22 - wordpress.com · (iv)dwell during the remaining 1800. draw the profile of the cam...

BTCE24,BTME22

IV SEMESTER B.TECH EXAMINATION, JANUARY-2013

SOLID MECHANICS

Time: 3 Hours Max. Marks: 75

GROUP A : Answer any three questions. (Question No. 1 is compulsory)

Q.1 A steel bar 30cm long, 5cm wide & 1.2cm thick is subjected to an axial pull of

8400 kg. Determine the change in length, width thickness & volume of bar.

Take E = 2 × 103 kg/cm2 & l/m = 0.32. (05)

Q.2 The stress component at a point are given by σx = σy = σz = 50 MPa,

Zxy = 10, zyz = 20 zxz = 15 MPa calculate the strain component taking E =

200 GPa & μ = 0.30 (10)

Q.3 Give the significance of theories of failure. (10)

Q.4 Under what axial tensile load, the diameter of a steel bar will be reduced from

8 cm to 7.995 cm? take E as 2.0 × 103 t/cm2 and Poisson’s ratio as 0.3. (10)

Q.5 A hollow circular column of 20 cm external and 16 cm internal diameter is 5

m long and fixed at both of its ends. It is subjected to a load of 12 tonnes at an

eccentricity of 2 cm from this geometrical axis. Determine the maximum

stress induced in the column section. Take E as 1.2 × 106 kg/cm2. (10)

GROUP B : Answer any three questions. (Question No. 6 is compulsory)

Q.6 Write Assumptions in the Euler’s Column theory. (05)

Q.7 Find the Rankne’s crippling load, if both the ends of the column are Hinged.

take σc = 8.5 σ t/cm2 & Rankine constant = 1 / 7500. (10)

Q.8 What is a failure theory? Discuss its importance Enumerate various failure

Theories & mention their field of application. (10)

Q.9 A steel bar 10 m long and 10 cm * 2.5 cm in section. It is subjected to an axial

pull of 250 kN. Determine the intensities of normal and tangential stresses on

a plane section at 60 to the longitudinal axis. (10)

Q.10 A test bar of certain material 4 cm in diameter when put to an axial pull of 200

kN recorded an extension of 0.0344 cm on gauge length of 15 cm and a

decrease of 0.0022 cm in diameter. Calculate Young’s modulus, poissson’s

ratio and Bulk modulus of the material. (10)

GROUP C: All Questions are Compulsory.

Q.11 Fill in the blanks (each question carries 2 marks)

(i) The material of the shaft is ________________ throughout.

(ii) The value of modulus of elasticity in Brass is _______________

(iii) The Coefficient of linear expansion in Aluminium is __________________

(iv) When shear force at a point is zero, then bending moment at that point will be

_____________

(v) In the theory of simply bending, the bending stress in the beam section varies

________________

Q.12 Multiple choice question. (Each question carries 2 marks)

(i) A body is said to be perfectly elastic, if it returns back

(a)Completely to its original shape and size

(b)To some extend to its shape & size

(c)Partially to its size

(d)None

(ii) Beyond the elastic limit the material gets into

(a)Plastic stage

(b)Solid stage

(c)Liquid stage

(d)None

(iii) When the deformation is prevented the stress included in the body is called

(a) Thermal stress

(b) Strain

(c) Pressure stress

(d) None

(iv) The value of Poisson’s ratio is same in

(a) Stress & strain

(b) Stress & tension

(c) Tension & compression

(d) None

(v) Due to torque every cross-section of the shaft is subjected to some

(a) Shear stress

(b) Shear strain

(c) Both (a) & (b)

(d) None

Q.13 True or false (each question carries 1 mark).

(i) The neutral axis of a section in an axis, at which the bending stress is infinity.

(ii) When a solid shaft is subjected to torsion, the shear stress induced in the shaft

at it center is zero.

(iii) The value of Poisson’s ratio in Concrete is .9 to 1.2

(iv) When a composite body is loaded, then strain and deformation will be equal

for all the members.

(v) The coefficient of linear expansion in cast iron is 11×10-6 to 12 × 10-6

******

BTME27


DYNAMICS Time: 3 Hours Max. Marks: 75


Q.1 State D’Alembert principle. (05)

Q.2 A 300 mm diameter 75 × 9.81 = 735.75 (N) flywheel has a mass of 75 kg and

is free to rotate about its mass centre. As inextensible rope is wrapped around

the rim of the flywheel and when a 10 kg block is attached to the rope, the

block is attached to the rope, the block attains a speed of 0.25 m/s after

moving down a distance of 0.6 m staring from rest. Compute the mass

moment of inertia of the flywheel and the tension in the rope. (10)

Q.3 Define the terms impulse of deformation & state what factors influence its

value for a pain of two materials. Can you suggest a simple experiment to

estimate the coefficient of restitution for a given pair of material. (10)

Q.4 Show that the energy expanded in enabling a body to escape the gravitational

field of the earth is twice the energy expended on it for a circular orbit at the

same launching position. (10)

Q.5 A ball is thrown vertically up with an initial velocity of 25 m/s. Calculate the

maximum altitude reached by the ball and the time t after throwing, for it to

return to the ground. Neglect air resistance and take the gravitational

acceleration to be constant at 9.81 m/s2. (10)


Q.6 Express the principle of work and energy for system of particles. (05)

Q.7 Give the relation between displacement velocity & time in case of a uniform

rectilinear motion. (10)

Q.8 State D’Alembert principle & explain plane motion of a rigid body. (10)

Q.9 State the principle of conservation of angular momenterum for a rigid today.

(10)

Q.10 Define the term coefficient of restitution & state what factors influence its

value for a pair of two material. (10)



(i) The magnitude of __________ is called speed.

(ii) Negative acceleration is called the ____________.

(iii) The unit of force in F.P.S is ____________.

(iv) A pair of axes about which the product of inertia vanishes is called________.

(v) According to the Routh’s rule the M.I about an axis of symmetry = _______.


(i) In CGS unit the of force is

(a) Poundal (b) pound (c) N-meter (d) Dyne

(ii) The product of mass &velocity of a body is

(a) Moment (b) Moment of inertia (c) Mass-velocity (d) Momentum

(iii) The rate of work done is

(a) Work (b) Powe (c) Energy (d) None

(iv) Pendulum holds a

(a)Linear motion (b) Circular motion (c) S.H.M (d) All

(v) According to Newton’2nd

law of motion

(a) m=Pf (b) P=mf (c) f=mp (d) None


(i) x/ t is the average velocity of the particle during the time interval ‘t’.

(ii) Force is something that change or tends to change the inertia of a body.

(iii) One watt = 108 ergs per sec.

(iv) Acceleration is also referred as retardation.

(v) In French system the unit of force is dyne.

******

BTME24


THEORY OF MACHINE



Q.1 Fig. Shows a brake shoe applied to a drum by a lever ab which is pivoted at a

fixed point a and rigidly fixed to the shoe. The radius of the drum is 160mm.

The coefficient of friction at the brake lining is 0.3. If the drum rotates

clockwise, find the braking torque due to the horizontal force of 600n at b.

(05)

Q.2 Calculate the whirling speed of a shaft 20 mm diameter & 0.6 m long carrying

a mass of 1 kg at its mid – point . The density of the shaft material is 40? (10)

Q.3 A differential band brake has a drum of diameter 800 mm. The two ends of the

band are fixed to the pins on the opposite sides of the fulcrum of the lever at a

distance of a=40 mm and b= 200 mm from the fulcrum. The angle of contact

is 2700 and = 0.2. Determine the brake torque when a force of 600N is

applied to the lever at a distance of 800 mm from the fulcrum when (10)

Q.4 A cam is to be designed for a knife edge follows with the following data:

(i)Cam lift = 40mm during 900 of cam rotation with simple harmonic motion.

(ii)Dwell for the next 300

(iii)During the next 600 of cam rotation the follower returns to its original

position with s.h.m.

(iv)Dwell during the remaining 1800.

Draw the profile of the cam when the line of stroke of the follower passes

through the axis of the cam shaft. The radius of the base circle of the cam is 40

mm. Determine the maximum velocity and acceleration of the follower during

its ascent and descent if cam rotates at 240 r.p.m. (10)

Q.5 Derive an expression to find out equilibrium speed for a Proell governor in

terms of governor height. (10)

(a) Drum rotates in the clockwise direction,

(b) Drum rotates in the anticlockwise direction.


Q.6 Distinguish between completed, incomplete and successful constraint of the

relative motion between two elements. (05)

Q.7 The crank and connecting rod of a theoretical steam engine are 0.5m and 2m

long respectively. The crank makes 180r.p.m. in the clockwise direction.

When it has turned 45 from the inner dead center position, determine: 1)

Velocity of position, 2) Angular velocity of connecting rod, 3) Velocity of

point E on the connecting rod 1.5m from the gudgeon pin, 4) Velocity of

rubbing at the pins of the crank shaft, crank and crosshead when the diameters

of their pins are 50mm, 60mm, and 30mm respectively,

5) Position and linear velocity of any point G on the connecting rod, which has

the least velocity relative to crankshaft. (10)

Q.8 Describe with neat sketch Ackermann steering gear mechanism. (10)

Q.9 What is effect of Gyroscopic couple on a Naval ship during steering? (10)

Q.10 Find the angle of inclination with respect to the vertical of a two wheeler

negotiating turn. Given: combined mass of the vehicle with its rider 250kg;

moment of inertia of the engine flywheel 5 times that of road wheels and in

the same direction; height of center of gravity of rider with vehicle 0.6m; two

wheelers speed 90km/hr’; wheel radius 300mm; radius of turn 50m. (10)



(i) The rope brake dynamometer is one of _________ dynamometer.

(ii) In a structure, the number of degree of freedom is ____________

(iii) The swaying couple is due to the __________unbalanced force.

(iv) All pairs are ______________pair in a pantograph.

(v) In a _________cam, the follower moves in direction perpendicular to the cam

axis.


(i) The contact ratio of gears is

(a) Zero (b) more than one

(c) less than one (d) none of these

(ii) The ratio of maximum displacement of the forced vibration to the deflection

due to the static force is known as

(a) Damping factor (b) Magnification factor

(c) Damping coefficient (d) logarithmic decrement

(iii) The mechanical brakes commonly used in trains is

(a) Shoe brake (b) band brake

(c) Band and block brake (d) internal expanding brake

(iv) When the sleeve of a porter governor moves upwards, the governor height

(a) increases (b) decreases (c) remains unaffected

(v) The coriolis component of acceleration is taken into account for

(a) Slider crank mechanism (b) Four bar chain mechanism

(c) Quick return motion mechanism (d) none of above.


(i) V-belts are used when the shafts are at along distance apart.

(ii) Acceleration of piston is independent of the length of connecting rod.

(iii) The height of a Watt’s governor does not depend upon the mass of the balls.

(iv) In the transmission dynamometer, the energy is not wasted in friction but is

used for doing work.

(v) Proell governor is a spring –controlled governor.

******

BTME29


HEAT TRANSFER - I



Q.1 Explain the heat flow in an infinitely thick plate (Semi-infinite body). (05)

Q.2 Explain system with negligible internal resistance lumped heat analysis.

(10)

Q.3 Explain system with finite surface and internal resistance. (10)

Q.4 What are Heisler charts? Explain their significance in solving transient

conduction problems? (10)

Q.5 Write a note on „Hydrodynamic boundary layer – Flat Plate. (10)


Q.6 Describe the mechanism of heat convection. (05)

Q.7 Write the Fourier rate equation for heat transfer by conduction Give the units

and physical significance of each term appearing in this equation. (10)

Q.8 Explain the mechanism of thermal conduction in gales, liquid, and solids,

discuss the effect of temperature on thermal conductivity. (10)

Q.9 What are Biot and Fourier numbers? Explain their physical significance. (10)

Q.10 Enumerate some of the empirical relations which are used to compute the

convective coefficient for free convection, in the product of Gr and Pr, what

group of properties is concerned only with the properties and gravitational

field? What is this group of properties, called? What are the dimensional units

of this group of properties? (10)



(i) Heat cannot flow from a body at _________________temperature

body at ___________ temperature without employing external work.

(ii) The flow region near the solid surface in which the effects of viscosity

are observed is called the ______________________.

(iii) The relationship between the two shape factors is known as

____________________.

(iv) Grashof number is expressed as ___________________.

(v) The region where the velocity gradients and viscous forces are

experienced by a flowingfluid is known as ____________________.


(i) The thermal conductivity of solid depends on their

(a)Molecular structure (b) Grain structure (c) Dimension (d) None of these

(ii) The ratio of the thermal resistance of internal – conduction to the thermal

resistance of surface- convection known as

(a) Reynold number (b) Grashof number (c) Biot number (d)none of

these

(iii) Thermal radiation emitted by a body is proportional to ________ power of its

absolute tmperature

(a) Second (b) Third (c) Fourth (d) One-half

(iv) Calulation of heat heat exchange between block bodies are simple because all

radiation received is

(a) Radiated (b) Absorbed (c) Refracted (d) none of these.

(v) For turbulent flow Grpr is

(a) <109

(b) =109

(c) >109

(d) None


(i) If the angle of incidence is equal to the angle of reflection, the reflection

is called specular.

(ii) The study of mass transfer is easy than heat transfer.

(iii) Thermal conductance is the reciprocal of Inductance.

(iv) In case of unsteady-state heat transfer, the boundary conditions are

strictly time Independent.

(v) Geometric “view factor” function is a function of the geometry and

orientation of the two bodies.

******

BTME31P-I

IV SEMESTER B TECH IN MECHANICAL ENGINEERING

EXAMINATION JANUARY-2013

SOLID MECHANICS

Time: 1 hours (5X5=25)

I. ANSWER ALL QUESTIONS.

1. Write a short note on complementary and normal shear stresses?

2. Explain Mohr's circle method for calculation of stresses?

3. Derive an equation for strain on an oblique plane?

4. Derive an equation for Biaxial normal strain with sheara strain?

5. Write a short note on Compatibility Equations?

BTME32P-II

IV SEMESTER B TECH IN MECHANICAL ENGINEERING

EXAMINATION JANUARY-2013

THEORY OF MACHINE

Time: 1 hours (5X5=25)

I. ANSWER ALL QUESTIONS.

1. Define the following terms:

a. Element

b. Higher pair

c. Lower pair

d. Kinematic chain

2. Distinguish between complete, Incomplete and successful constraint of the relative

motion between two elements or links.

3. Distinguish between a flywheel and governor.

4. What mass attached to the spring of problem 1 would result in a natural frequency of

100 cycles per minute?

5. Explain the Davis Steering Gear.

BSC06

Fourth Semester B. Tech (CS), Examination Dec/Jan 2012-13

Society, Environment & EngineeringTime:-3Hours Max. Marks: - 75

SECTION-A

Attempt any five Questions. (5*5)

1. What is the significance of sociology in modern society?

2. What is community?

3. Define Socialization.

4. What is social change?

5. What is social control?

6. Define the term ‘Civilization’?

7. What is communism or Marxism?

SECTION-B

Attempt any two Questions. (10*2)

8. What is technological forecasting and up gradation?

9. Define optimization. Discuss its basic concepts.

10. What are the main sources of air pollution? Discuss each in brief?

SECTION-C

Attempt any two Questions. (15*2)

11. What is man power planning? Describe the need for man power planning?

12. What are the different types of trainings in the industry?

13. Write short note on-

(1) Motivation

(2) Communication

btce24,btme22 - wordpress.com · (iv)dwell during the remaining 1800. draw the profile of the cam...

Documents