NEET Solved Paper 2019 Question 5

Question: Under isothermal condition, a gas at 300 K expands from 0.1 L to 0.25 L against a constant external pressure of 2 bar. The work done by the gas is [Given that 1 L bar = 100 J] [NEET 5-5-2019]

Options:

A) 25 J

B) 30 J

C) -30 J

D) 5 Kj

Show Answer

Answer:

Correct Answer: C

Solution:

Thermodynamics $ W=P _{ext}\Delta V $ = -2(bar) (0.15 L) = -0.3 bar: = -0.3 × 100 J = - 30 J