A perfect gas goes from a state A to another state B by absorbing 8 × 105 J of heat and doing 6.5 × 105 J of external work. It is now transferred between the same two states in another process in which it absorbs 105 J of heat. In the second process

Options

A. Work done on the gas is `0.5xx10^5J`
B. Work done by gas is `0.5xx10^5J`
C. Work done on gas is `10^5J`
D. Work done by gas is `10^5J`

Answer

A

Explanation

Process 1:
`DeltaQ=DeltaU+DeltaW`
`8xx10^5=DeltaU+6.5xx10^5`
`DeltaU=1.5xx10^5J`
Process 2: `DeltaQ=DeltaU+DeltaW`
`10^5=1.5xx10^5+DeltaWimpliesDeltaW=-0.5xx10^5J`