If `DeltaU` and `DeltaW` represent the increase in internal energy and work done by the system respectively in a thermodynamical process which of the following is true?

Options

A. `DeltaU=-DeltaW` , in an adiabatic process
B. `DeltaU=DeltaW`, in an isothermal process
C. `DeltaU=DeltaW` in an adiabatic process
D. `DeltaU=-DeltaW` in an isothermal process

Answer

A

Explanation

According to first law of thermodynamics ,
`DeltaQ=DeltaU+DeltaW`
For an adiabatic process `DeltaQ=0`
`therefore DeltaU=-DeltaW`
For an isothermal process,
`DeltaU=0`
`therefore DeltaQ=DeltaW`