The graph between volume and temperature in Charles’ law is

(a)

an ellipse

(b)

a circle

(c)

a straight line

(d)

a parabola

When food is cooked in a vessel by keeping the lid closed, after some time the steam pushes the lid outward. By considering the steam as a thermodynamic system, then in the cooking process

(a)

Q > 0, W > 0,

(b)

Q < 0, W > 0,

(c)

Q > 0, W < 0,

(d)

Q < 0, W < 0,

A hot cup of coffee is kept on the table. After some time it attains a thermal equilibrium with the surroundings. By considering the air molecules in the room as a thermodynamic system, which of the following is true

(a)

ΔU > 0, Q = 0

(b)

ΔU > 0, W < 0

(c)

ΔU > 0, Q > 0

(d)

ΔU = 0, Q > 0

Identify the state variables given here?

(a)

Q, T, W

(b)

P, T, U

(c)

Q, W

(d)

P, T, Q

The efficiency of a heat engine working between the freezing point and boiling point of water is

(a)

6.25%

(b)

20%

(c)

26.8%

(d)

12.5%

1 mole of a gas with \(\gamma =\frac { 7 }{ 5 } \)  is mixed with 1 mole of gas with \(\gamma =\frac { 5 }{ 3 } \) then value of g of the resulting mixture is ____________.

(a)

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

(b)

\(\frac { 2 }{ 5 } \)

(c)

\(\frac { 3 }{ 2 } \)

(d)

\(\frac { 12 }{ 7 } \)

One kg of a diatomic gas is at a pressure of 8\(\times\)10⁴ N/m2 the density of the gas is 4kglm^g What is the energy of the gas due to its thermal mole ______________.

(a)

3\(\times\)10⁴ J

(b)

5\(\times\)10⁴ J 

(c)

6\(\times\)10⁴ J

(d)

7\(\times\)10⁴ J

 Surface of the lake is at 2°C and depth of the lake is 20m find the temperature of the bottom of the lake ______________.

(a)

2⁰C

(b)

3⁰C

(c)

4⁰C

(d)

none of the above

Graph of specific heat at constant volume for a mono atomic gas is _______________.

(a)

(b)

(c)

(d)

In an adiabatic system which is true?

(a)

\({ P }^{ \gamma }{ T }^{ \gamma -1 }\) = Constant

(b)

\({ P }^{ \gamma }{ T }^{ 1-\gamma }\) = Constant

(c)

\({ PT }^{ \gamma }\) = Constant

(d)

\({ P }^{ 1-\gamma }{ T }^{ \gamma }\) = Constant

Universal gas constant is _________________.

(a)

C_p/C_v

(b)

C_p - C_v

(c)

C_p + C_v

(d)

C_v/C_p

A process in which the temperature of working substance remains constant during its expansion or compression ____________________.

(a)

isothermal

(b)

adiabatic

(c)

isobaric

(d)

isochoric

The specific heat of water is ________________.

(a)

1.817

(b)

25.12

(c)

4.187

(d)

none

When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This is _____________.

(a)

Kelvin Planck law

(b)

first law of thermodynamics

(c)

zeroth law of thermodynamics

(d)

second law of thermodynamics

The coefficient of volume expansion of a solid is x times the coefficient of superficial expansion. Then x is _____________.

(a)

1.5

(b)

2

(c)

2.5

(d)

3

A block of wood is floating on water at 0^oC with a certain volume V above water level. The temperature of water is slowly raised to 20^oC. How does the volume V change with the rise of temperature?

(a)

remain unchanged

(b)

decrease continuously

(c)

decrease till 4°C and then increase

(d)

increase till 4°C and then decrease

A steel rod of length 25 cm has a cross-sectional area of 0.8 cm². The force required to stretch this rod by the same amount as the expansion produced by heating it through woe is ___________ (coefficient of linear expansion of steel is 10^-5/^oC and Young's modulus of steel is 2\(\times\)10¹⁰ N/m²)

(a)

40 N

(b)

80 N

(c)

120 N

(d)

160 N

A perfect gas at 27°C is heated at constant pressure so as to double its volume. The temperature of the gas becomes _____________.

(a)

54°C

(b)

150K

(c)

327°C

(d)

327K

Two vessels A and B contain the same ideal gas. The volume of B is twice that of A, the pressure in B is twice that in A and the temperature of B is twice that of A. The ratio of the number of gas molecules in A and B is _______________.

(a)

1:2

(b)

2:1

(c)

1:4

(d)

4:1

The pressure of a gas contained in a closed vessel is increased by 0.4% when heated by 1°C. The initial temperature was ____________________.

(a)

250 K

(b)

250°C

(c)

25 K

(d)

25^oC