A fixed mass of helium gas is made to undergo a process in which its pressure varies linearly from `1 kPa` to `2 kPa`, in relation to its volume as the latter varies from `0.2 m^(3)` to `0.4 m^(3)`. The heat absorbed by the gas will be

Options

A. `300 J`
B. `900 J`
C. `1200 J`
D. `1500 J`

Answer

C

Explanation

c. `Delta W = (1)/(2) (1 + 2) xx 10^(3) N//m^(2) xx (0.4 - 0.2) m^(3) = 300 J`
`Delta U = n C_(V) Delta T = ((P_(2) V_(2) - P_(1) V_(1)))/(gamma -1)`
`= (3//2) (0.4 xx 2 = 0.2 xx 1) xx 103 J = 900 J`
`Delta Q = Delta W + Delta U = 1200 J`