Question

Heat is given to an ideal gas in an isothermal process
A Internal energy of the gas will decrease
B Internal energy of the gas will increase
C Internal energy of the gas will not change
D The gas will do positive work E The gas will do negative work
Choose the correct answer from the options given below:

• A. C and D only
• B. B and D only
• C. A and E only
• D. C and E only

Answer 1

Answer: (A)

C and D only

Answer 2

Sol. dQ=dU+dW
⇒dU=nCV​dT
dU=0 (for isothermal)
∴U= constant
Also dQ>0 (supplied)
Hence dW>0