If a wire is stretched to double of its original length, then the strain in the wire is

(a)

1

(b)

2

(c)

3

(d)

4

For a given material, the rigidity modulus is \(\left( \frac { 1 }{ 3 } \right) \)^rd of Young’s modulus. Its Poisson’s ratio is

(a)

0

(b)

0.25

(c)

0.3

(d)

0.5

Two wires are made of the same material and have the same volume. The area of cross sections of the first and the second wires are A and 2A respectively. If the length of the first wire is increased by Δl on applying a force F, how much force is needed to stretch the second wire by the same amount?

(a)

2 F

(b)

4 F

(c)

8 F

(d)

16 F

The young’s modulus for a perfect rigid body is

(a)

0

(b)

1

(c)

0.5

(d)

infinity

If the temperature of the wire is increased, then the Young’s modulus will 

(a)

remain the same

(b)

decrease

(c)

increase rapidly

(d)

increase by very a small amount

A certain number of spherical drops of a liquid of radius R coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

(a)

energy = 4 V T \(\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right) \)is released

(b)

energy = 3 V T \(\left( \frac { 1 }{ r } +\frac { 1 }{ R } \right) \)is absorbed

(c)

energy = 3 V T \(\left( \frac { 1 }{ r } -\frac { 1 }{ R } \right) \)is released

(d)

energy is neither released nor absorbed

The wettability of a surface by a liquid depends primarily on

(a)

viscosity

(b)

surface tension

(c)

density

(d)

angle of contact between the surface and the liquid

An air bubble of diameter 4 mm rises steadily i through a solution of density 1500 kgm²³ at the rate of 30cm^-1 the coefficient of viscosity of the solution is _____________.

(a)

3.3\(\times\)10^-3 poise

(b)

2.2\(\times\)10^-3 poise

(c)

3.3\(\times\)10^-3 poise

(d)

4.4\(\times\)10^-3 poise

Water rises in a capillary tube to a certain height such that the upward force due to the surface tension is balanced by 62.84\(\times\)10^-5N force due to the weight of the liquid column. If the surface tension of water is 70\(\times\)10^-3Nm the radius of the capillary tube is ____________.

(a)

1.43\(\times\)10^-3m

(b)

2.83\(\times\)10^-3 m

(c)

1.43\(\times\)10^-2 m

(d)

2.83\(\times\)10^-3 m

Ablack body is continuously radiating measured at a temperature of 2880 k if U₁ U₂ and U₃ are the amount of radiation measured between the wavelengths 599 & 600 nm, 999 & 1000 nm & 1499 & 1500 nm respectively then _____________ (wiresconstant b = 2.88\(\times\)10²⁶ kmk)

(a)

U₂ < U₃

(b)

U₁ = U₂ = U₃

(c)

U₁23

(d)

U₂ >U₁ >U₃

If there were no gravity, which of the following will not be there for a fluid?

(a)

viscosity

(b)

surface tension

(c)

pressure

(d)

archimedes upward thrust

Critical velocity of the liquid _____________.

(a)

decreases when radius decreases

(b)

increases when radius increases

(c)

decreases when density increases

(d)

increase when density increases

A rectangular vessel when full of water, takes 10 min to be emptied through an orifice in its bottom, how much time will it take to be emptied when half filled with water _____________.

(a)

9 min

(b)

7 min

(c)

5 min

(d)

3 min

Two drops of equal radius coalesce to form a bigger drop. What is ratio of surface energy of bigger drop to smaller one?

(a)

2^1/2:1

(b)

1:1

(c)

2^2/3:1

(d)

none of these

Two capillaries of lengths L & 2L and of radius R & 2R are connected in series the net rate of flow of fluid through them will (rate of the flow through singe capillary,\(x=\pi R^{4}/8 \eta L\)) be ____________.

(a)

\(\frac{8}{9}\alpha\)

(b)

\(\frac{9}{8}\alpha\)

(c)

\(\frac{5}{7}\alpha\)

(d)

\(\frac{7}{5}\alpha\)

The water from a tap of diameter 1.25cm with a rate of 5\(\times\)10^-5m³s^-1 the density & coefficient of viscosity of water are 10³ kg m^-3 & 10^-3 pascal the flow of water is ______________.

(a)

steady with Reynold's number 5100

(b)

turbulent with Reynold's number 5100

(c)

steady with Reynold's number 3900

(d)

turbulent with Reynold's number 3900

The CGS unit of stress is ______________.

(a)

N/m²

(b)

J/m²

(c)

dynl/cm²

(d)

N/cm²

Amount of energy required to change liquid to gas and vice versa without any change in temperature is termed as __________________.

(a)

Latent Heat and Fusion

(b)

Latent Heat of Yaporis ation

(c)

Heat capacity

(d)

Specific heat capacity

Energy due to which molecules held at a fixed position vibrate, this energy is termed as______________.

(a)

external energy

(b)

internal energy

(c)

chemical energy

(d)

physical energy

The viscous force the relative motion between the adjacent layers of a fluid in motion which one of the following is absolutely fit?

(a)

opposes

(b)

never affects

(c)

facilitates

(d)

may effect under certain conditions