The average degree of freedom per molecule for a gas is 6. The gas performs 25 J of work when it expands at constant pressure. The heat absorbed by the gas is

Options

A. `75 J`
B. `100 J`
C. `150 J`
D. `125 J`

Answer

B

Explanation

b. As `f = 6` (given), therefore
`gamma = 1 + (2)/(f) = 1 + (2)/(6) = (4)/(3)`
Fraction of energy given for external work
`(Delta W)/(Delta Q) = (1 - (1)/(gamma))`
`implies (25)/(Delta Q) = (1 - (1)/(4//3)) = 1 - (3)/(4) = (1)/(4)`