Question

The external work done when air expands from 10 litres to 15 litres at a pressure of 2 atm is:

• A. 10 J
• B. 1000 J
• C. 2000 J
• D. 20 J

Hint:

The work done during the expansion or compression of an ideal gas is given by \( W = P \Delta V \), where \( \Delta V \) is the change in volume and \( P \) is the constant pressure.

Answer 1

The Correct Option is B

The work done during expansion or compression is given by: \[ W = P \Delta V \] Where: - \( P = 2 \times 10^5 \, \text{Nm}^2 \) (pressure), - \( \Delta V = V_2 - V_1 = (15 - 10) \, \text{litres} = 5 \times 10^{-3} \, \text{m}^3 \). Substitute the values: \[ W = 2 \times 10^5 \times 5 \times 10^{-3} = 1000 \, \text{J} \] Thus, the work done is 1000 J.