The work done in changing the state from `(P_0, V_0)` to `(P_1, V_1)` in the following system is :

Options

A. `-7.5xx10^(-5) J`
B. `-7.5 xx10^(5) J`
C. `-7.5xx10^(5) erg`
D. `-7.5xx10^(-5)` erg

Answer

B

Explanation

`DeltaW=-intPDeltaV`= Area under `P-V` curve

=[are of square+area of triangle]
`=-[P_(0)(V_(1)-V_(0))+1/2(P_(1)-P_(0))xx(V_(1)-V_(0))]`
`-[P_(0)(V_(1)-V_(0)+1/2P_(1)(V_(1)-V_(0))-1/2P_(0)(V_(1)-V_(0))]`
`=-[1/2P_(0)(V_(1)-V_(0)+1/2P_(1))(V_(1)-V_(0))]`
`=-1/2[P_(0)+P_(1)][V_(1)-V_(0)]`
`=-1/2[(1+4)xx10^(5)]xx[4-1]`
`=-7.5xx10^(5) J`