A gas expands against a variable pressure given by `P=(20)/(V)` bar. During expainsion from volume of `1` litre to `10` litre, the gas undergoes a change in internal energy of `400 J`. Heat absorbed by the gas during expansion ( in `KJ`):

Answer

5

Explanation

`Delta W=underset(1)overset(-10)intPdv= -20underset(1)overset(10)int(dv)/(V)=20[ l n(V)]_(1)^(10)= -20 ln(10)= -4605 J`
`Delta q=Delta U-Delta w`
`= 400-(-4605)=5005 J ~~ 5 KJ`