Concepts Of Physics MCQ Edition [Volume 2]PhysicsSpecific Heat Capacities of Gases
An ideal gas ( = 1.5 ) initially at 300 K and 100 kPa with a volume of 1 litre is suddenly compressed to half its original volume. What is the change in the internal energy of the gas?
Options
- A82.8 J
- B-82.8 J
- C41.4 J
- D-41.4 J
Correct answer
A. 82.8 J
Step-by-step solution
According to the first law of thermodynamics, Q = U + W . Since the sudden compression is an adiabatic process, there is no heat exchange, so Q = 0 . This implies the change in internal energy is U = -W . Using the work done calculated previously, U = -(-82.8 J ) = 82.8 J .