Physics of Solids MCQs

Question 1

A body floats in a liquid contained in a beaker. The whole system, as shown, falls freely under gravity. The upthrust on the body due to the liquid is:

Accepted Answer

Zero

Answer

Equal to the weight of the liquid displaced

Answer

Equal to the weight of the body in air

Answer

Equal to the weight of the immersed position of the body

Question 2

What is the Young's modulus of elasticity for a perfectly rigid body?

Accepted Answer

Infinity

Answer

Zero

Answer

1

Answer

-1

Question 3

Two stretched membranes of area 2 cm2 and 3 cm2 are placed in a liquid at the same depth. The ratio of pressures on them is:

Accepted Answer

1 : 1

Answer

2 : 3

Answer

3 : 2

Answer

22 : 32

Question 4

Water enters through end A with speed v1 and leaves through end B with speed v2 of a cylindrical tube AB. The tube is always completely filled with water. In case I the tube is horizontal and in case II it is vertical with end A upwards and in case III it is vertical with end B upwards. We have v1=v2 for:

Accepted Answer

Each case

Answer

Case I

Answer

Case II

Answer

Case III

Question 5

Two solid spherical balls of radius r1 & r2 (r2 < r1) and density σ are tied up with a string and released in a viscous liquid of lesser density ρ and coefficient of viscosity η, with the string just taut as shown. The terminal velocity of the spheres is:

Accepted Answer

Option C: vt = (2/9) * (σ - ρ) * g * (r1² + r2²) / (2 * η)

Answer

Option A: vt = (2/9) * (σ - ρ) * g * r1² / η

Answer

Option B: vt = (2/9) * (σ - ρ) * g * r2² / η

Answer

Option D: vt = (4/9) * (σ - ρ) * g * r1 * r2 / η

Question 6

Two elastic rods are joined between fixed supports as shown in the figure. The condition for no change in the lengths of individual rods with the increase of temperature is: (α1,α2 = linear expansion coefficient, A1, A2 = area of rods, Y1,Y2 = Young's modulus)

Accepted Answer

A1/A2 = (α2 * Y2) / (α1 * Y1)

Answer

A1/A2 = (α1 * Y1) / (α2 * Y2)

Answer

A1/A2 = (L1 * α1 * Y1) / (L2 * α2 * Y2)

Answer

A1/A2 = (L2 * α2 * Y2) / (L1 * α1 * Y1)

Question 7

A wire of length '2m' is clamped horizontally between two fixed supports. A mass m = 5 kg is hung from the middle of the wire. The vertical depression in the wire in equilibrium is: (Young's modulus of wire = 2.4 x 10^9 N/m2, cross-sectional area = 1 cm2)

Accepted Answer

4.68 cm

Answer

1.52 cm

Answer

1.12 cm

Answer

0.58 cm

Question 8

A gas undergoes a process in which the pressure and volume are related by VPn = constant. The bulk modulus of the gas is :

Accepted Answer

P/n

Answer

nP

Answer

P1/n

Answer

Pn

Question 9

The adjacent graph shows the extension (∆l) of a wire of length λ m suspended from the top of a roof at one end and with a load W connected to the other end. If the cross-sectional area of the wire is 10-6 m2, calculate the Young's modulus of the material of the wire:

Accepted Answer

2 x 10^11 λ N/m2

Answer

2 x 10^-11 λ N/m2

Answer

3 x 10^12 λ N/m2

Answer

2 x 10^13 λ N/m2

Question 10

Two wires of equal length and cross-section are suspended as shown. Their Young's moduli are Y1 and Y2, respectively. The equivalent Young's modulus will be:

Accepted Answer

(Y1 + Y2) / 2

Answer

Y1 + Y2

Answer

(Y1 * Y2) / (Y1 + Y2)

Answer

√(Y1 * Y2)

Question 11

In a wire stretched by hanging a weight from its end, the elastic potential energy per unit volume in terms of longitudinal strain σ and modulus of elasticity Y is:

Accepted Answer

Yσ²/2

Answer

Yσ/2

Answer

2Yσ²/2

Answer

Y²σ/2

Question 12

A ball falling in a lake of 200 m shows a decrease of 0.1% in its volume. The bulk modulus of elasticity of the material of the ball is: (take g =10 m/s2)

Accepted Answer

2 x 10^9 N/m2

Answer

109 N/m2

Answer

3 x 10^9 N/m2

Answer

4 x 10^9 N/m2

Question 13

The rubber cord catapult has a cross-sectional area of 1 mm2 and a total unstretched length of 10 cm. It is stretched to 12 cm and then released to project a stone of mass 5 g. Taking Young's modulus Y of rubber as 5 x 10^8 N/m2, the velocity of projection will be:

Accepted Answer

20 m/s

Answer

20 cm/s

Answer

2 m/s

Answer

None of these

Question 14

A U-tube in which the cross-sectional area of the limb on the left is one-quarter, and the limb on the right contains mercury (density 13.6 g/cm3). The level of mercury in the narrow limb is at a distance of 36 cm from the upper end of the tube. What will be the rise in the level of mercury in the right limb if the left limb is filled to the top with water?

Accepted Answer

0.56 cm

Answer

1.2 cm

Answer

2.35 cm

Answer

0.8 cm

Question 15

A piston of a cross-sectional area of 100 cm2 is used in a hydraulic press to exert a force of 107 dynes on the water. The cross-sectional area of the other piston which supports an object having a mass of 2000 kg is:

Accepted Answer

2 x 10^4 cm2

Answer

100 cm2

Answer

109 cm2

Answer

2 x 10^10cm2

Question 16

There are _ types of solids.

Accepted Answer

Two

Answer

One

Answer

Three

Answer

Four

Question 17

The matter which has definite shape is

Accepted Answer

Solid

Answer

Gas

Answer

Liquid

Answer

Plasma

Question 18

Which one of the following is BCC?

Accepted Answer

All of the above

Answer

Fe

Answer

Cr

Answer

Tungsten

Question 19

Which one of the following is FCC?

Accepted Answer

All of these

Answer

Zn

Answer

Cadmium

Answer

Magnesium

Question 20

Which one of the following are amorphous?

Accepted Answer

Charcoal

Answer

Ruby stone

Answer

Glass

Answer

Both a & b

Free Physics of Solids MCQs with Answers