JEE Advanced2012PhysicsThermodynamicsActual
Two moles of ideal helium gas are in a rubber balloon at 30^ C . The balloon is fully expandable and can be assumed to require no energy in its expansion. The temperature of the gas in the balloon is slowly changed to 35^ C . The amount of heat required in raising the temperature is nearly (take R=8.31 ~J / mol . K )
Options
- A62 ~J
- B104 ~J
- C124 ~J
- D208 ~J
Correct answer
D. 208 ~J
Step-by-step solution
The heat is supplied at constant pressure. i.e., the process is isobaric array l Q=n C_ p t =2 [ 5 2 R ] t=2 5 2 8.31 5=208 ~J ( C_ p = 5 2 R for mono-atomic gas ) array