1 The specific heat of a substance at its boiling point or melting point

Is 0

Is infinity

Is negative

lies between 0 and 1

2 A unit mass of solid converted to liquid at its melting point. Heat is required for this process is

Specific heat

Latent heat of vaporization
Latent heat of fusion

External latent heat

3 At a certain temperature, hydrogen molecules have r.m.s. velocity of 3 km/s. what is the r.m.s velocity of the oxygen molecules at the same temperature?

0.25 km/s

0.5 km/s

0.75 km/s

0.6 km/s

4 Which one of the following quantities can be zero on a average for the molecules of an ideal gas in equilibrium?

Kinetic energy

Density

Momentum

Speed

5 The specific heat of a gas

Has only one value

No answer

Is proportional to the square root of its absolute temperature

Can have any value between 0 and infinity

6 At constant volume temperature is increased then

Collision on walls will be less

Collision frequency will be increases

Collision will be in straight line

Collision will not change

7 A sample of an ideal gas occupies a volume V at a pressure P and absolute temperature T, the mass of each molecules is m. the expression for the density of gas is (k = Boltzmann constant

mkT

P/kT

P/kTV

Pm/kT

8 If for a gas
R/CV=0.67
this gas is made up of molecules which are

Diatomic

Mixture of diatomic and polyatomic

Mono atomic

Polyatomic

9 The specific heat of a substance at its boiling point or melting point

0

infinity

negative

between 0 and 1

10 Mass of gas is 300 gm and its specific heat at constant volume is 750 J/kg K. if gas is heated through 75°C at constant pressure of 105 N/{m^2}, it expands by volume
0.08×106cm3
. find
CP/CV
.

1.4

1.374

1.474

1.5

11 A solid ball with a mass m = 0.53 kg floats in a tank of water. The ball is made of material with a density of 400
kg/m3
. The density of water is 1000
kg/m3
. What fraction of the volume of the ball is below the waterline?

0.1

0.2

0.3

0.4

12 A slab of wood with mass m = 1.7 kg floats 78% submerged.The density of water is 1000
kg/m3
. What is the density of the wood?

720
kg/m3
780
kg/m3
850
kg/m3
900
kg/m3

13 A solid X is in thermal equilibrium with a solid Y, which is at the same temperature as a third solid Z. The three bodies are of different materials and masses. Which one of the following statements is certainly correct? of 164.9J/s, calculate the the thermal conductivity of aluminum

X and Y have the same heat capacity

X and Y have the same internal energy

It is not necessary that Y should be in thermal equilibrium with Z

There is no net transfer of energy if X is placed in thermal contact with Z

14 A hot water tank of heat capacity 5000 JK-1 contains 10 kg of water at 25 °C. What is the time taken to raise the temperature of the water to 45 °C using a heater coil of power of 3.0 kW, given that the specific heat capacity of water is 4200 Jkg-1 K-1?

61 s

280 s

310 s

610 s

15 A solid object M is made of a material with a specific capacity c and a specific latent heat of fusion L.The object is heated up at a constant rate P. Its initial temperature is below its melting point by ΔT. The time for the object to be completely melted is given by

M(cΔT + L)/P

M(c + L)ΔT/P

P/[mΔT(c + L)]

P/[m(cΔT + L)]

16 A student tries to determine the specific latent heat of vaporisation of a liquid by an electrical method. A heater is used to boil the liquid and when the liquid is boiling, the mass of liquid vaporised per second is measured at two different powers for the heater. At the power of 40 W and 80 W, the liquid is vaporised at the rate of 0.0417
kgs−1
and 0.0893
kgs−1
respectively. What is the best estimate of the specific latent heat of vaporisation of the liquid?

840Jkg−1

896Jkg−1

928Jkg−1

959Jkg−1

17 The temperature 47.12 °C is equivalent to

320.28 K

320.27 K

-226.03 K

-226.04 K

18 A gas cylinder is fitted with a safety valve which releases a gas when the pressure inside the cylinder reaches
2.0x106Pa
. Given the maximum mass of this gas that the cylinder can hold at 10 °C is 15 kg, what would be the maximum mass at
30∘C
?

5 kg

14 kg

20 kg

45 kg

19 2 bulbs X and Y are filled with an ideal gas and connected by a capillary tube. The volume of bulb X is three times that of bulb Y. The number of gas molecules in X and Y are 2N and N respectively. If the temperature of the gas in Y is 300 K, what is the temperature of the gas in X

150 K

200 K

450 K

600 K

20 An ideal gas is contained in two metal cylinders X and Y connected by a tap which is initially closed. The volume and pressure of the gas in the cylinders are as attached.When the tap connecting the two cylinders is opened, what will be the final pressure, in Pa, in the vessel? Assume that the temperature remains constant
Click here to see exhibit

2.4×105

3.5×105

4.2×105

5.0×105