2019-03-01_Physics_Times

One mole of a monoatomic ideal gas is expanded

by a process described by PV C^3  where C is

a constant. The heat capacity of the gas during the

process is given by (R is the gas constant)

(a) 2R (b)

5

2

R (c)

3

2

R (d) R

The bulk modulus of a gas is defined as B

VdP

dV



.

For an adiabatic process the variation of B is pro-

portional to Pn.For an idea gas,n is

(a) 0 (b)1 (c)

5

2

(d) 2

In the P-V diagram below the dashed curved line is

an adiabat.

For a process that is described by a straight line

joining two points X and Y on the adiabat (solid

line in the diagram) heat is:(hint: consider the varia-

tions in temperature from X to Y along the straight

line)

(a) Absorbed throughout from X to Y

(b) Released throughout from X to Y

(c) Absorbed from X up to an intermediate point

Z(not shown in the figure) and then released

from Z to Y

(d) Released from X up to an intermediate point

Z(not shown in the figure) and then released

from Z to Y

The three process in a thermodynamic cycle shown

in the figure are: Processes 12 is isothermal

isothermal; Process 23 is isochoric(volume re-

mains constant);process 31 is adiabatic. The

total work done by the ideal gas in this cycle is

10J.The internal energy decreases by 20J in the

isochoric process. The work done by the gas in

the adiabatic process is -20J.The heat added to the

system in the isothermal process is

The heat capacity of one mole an ideal gas is found

to be C 3R / 1 / RT / 2V  a  where a is a con-

stant. The equation obeyed by this gas during a

reversible adiabatic expansion is

(a) TV e3/2aRTconstant

(b) TV e3/2 3 /2aRT constant

(c) TV3/2constant

(d) TV e3/2 2 /3aRT constant

The state of an ideal gas was changed is-

obarically.The graph depicts three such isobaric

lines.Which of the following is true about the pres-

sures of the gas?

(a) P P P 1   2 3 (b) P P P 1   2 3

(c)P P P 1   2 3 (d) P P P P 1 / 2  3 / 1

An ideal gas undergoes a circular cycle centered

at 4 atm,4 lit as shown in the diagram. The maxi-

mum temperature attained in this process is close

to

11.

[2014]

12.

[2013]

13.

[2013]

14.

[2013]

[2016]

[2015]

[2015]

[2014]

(a) 30/R (b) 36/R (c) 24/R (d) 16/R
An ideal gas follows a process described by

PV C^2  from P V T1 1 1, ,  to P V T2 2 2, , (C is a

constant). Then

(a) IfP P 1  2 thenT T 2  1

(b) IfV V 2  1 thenT T 2  1

(c) If V V 2  1 thenT T 2  1

(d) If P P then V V 1  2 1  2