Question

Given below are two statements
Statement-I: When μ amount of an ideal gas undergoes adiabatic change from state (P 1, V 1, T 1) to state (P 2, V 2, T 2), then work done is
$W = \frac{μR(T2 - T1)}{1 - γ}$
,where
$γ = \frac{Cp}{Cv}$and R = universal gas constant.
Statement-II: In the above case, when work is done on the gas, the temperature of the gas would rise.
Choose the correct answer from the options given below.

• A. Both statement-I and statement-II are true
• B. Both statement-I and statement-II are false
• C. Statement-I is true but statement-II is false
• D. Statement-I is false but statement-II is true

Answer 1

Answer: (A)

Both statement-I and statement-II are true

Answer 2

The correct answer is (A) : Both statement-I and statement-II are true
$W = \frac{μR(T2 \- T1)}{1 - r}$
for a polytropic process for adiabatic process r = γ
⇒ Statement I is true
In an adiabatic process
Δ U = –Δ W
⇒ If work is done on the gas
⇒ Δ W is negative
⇒ Δ U is positive or temperature increases
⇒ Statement II is true