Question

2 kg of air is contained in a closed system at a pressure of 2 bar and 0.5 m³. It undergoes an isobaric expansion till the final volume becomes 0.6 m³. The work transfer (in kJ) during the process is:

• A. -20
• B. -10
• C. +20
• D. +10

Hint:

In an isobaric process the work done is simply the pressure multiplied by the change in volume Make sure to convert all units properly e.g converting bar to Pa and ensuring the volume is in cubic meters.

Answer 1

The Correct Option is C

For isobaric expansion, the work done (\( W \)) is given by the equation:

\( W = P \Delta V \)

Where \( P = 2 \, \text{bar} = 2 \times 10^5 \, \text{Pa} \), and the volume change \( \Delta V = V_2 - V_1 = 0.6 \, \text{m}^3 - 0.5 \, \text{m}^3 = 0.1 \, \text{m}^3 \).
So,

\( W = 2 \times 10^5 \, \text{Pa} \times 0.1 \, \text{m}^3 = 20 \, \text{kJ}. \)

Thus, the work transfer is \( +20 \, \text{kJ} \).