2019-03-01_Physics_Times

An ideal gas undergoes change in its state from

the initial state I to the final state F via two pos-

sible paths as shown. Then

(a) There is no change in internal energy along

path1.

(b) Heat is not absorbed by the gas in both paths.

(c) The temperature of the gas first increases

and then decreases for path 2.

(d) Work done by the gas is larger in path1.

For an ideal gas the internal energy is given by

U PV5 / 2C , where C is a constant. The equa-

tion of the adiabats in the PV plane will be

(a) P V5 7Constant (b)P V7 5Constant
(c) P V3 5Constant (d) P V5 2Constant
Insulated rigid container of one litre volume con-
tains a diatomic ideal gas at room temperature. A
small paddle installed inside the container is ro-
tated from the outside such that the pressure rises
by 105 pa. The change in internal energy is close
to
(a) 0J (b) 67J (c) 150J (d) 250J
An ideal gas is made to undergo the cyclic pro-
cess shown in the figure below. Let W depict
the work done. U be the change in internal en-
ergy of the gas and Q be the heat added to the gas.
Sign of each of these three quantities for the whole
cycle will be (0 refers to no change)

(a)  ,0, (b)  ,0, (c) 0,0,0 (d)   , ,

A gas at initial temperature T. undergoes sudden

expansion from volume V to 2V. Then

(a) The process is adiabatic

(b) The process is isothermal

(c) The work done in this process is nRTne (^2) 
where n is the number of moles of the gas.
(d) The entropy in the process does not change
An ideal gas is taken reversibly around the cycle a-
b-c-d-a as shown on the T (temperature)-S(entropy)
diagram
The most appropriate representation of above
cycle on a U (internal energy)-V (volume) diagrame
is
(a) (b)
(c) (d)
Thermodynamics

1. [2018]


2. 
   

   [2018]

   
   


3. 
   

   [2018]

   
   


4. 
   

   [2018]

   
   


5. 
   

   [2016]

   
   


6. 
   

   [2016]