Question

A diatomic gas, having $C_{p}=\frac{7}{2} R$ and $C _{ v }=\frac{5}{2} R ,$ is heated at constant pressure. The ratio $dU : dQ : dW$

• A. 5: 7: 3
• B. 5: 7: 2
• C. 3: 7: 2
• D. 3: 5: 2

Answer 1

Answer: (B)

$d U = n C _{ v } d T$
$d Q = n C _{ p } d T$
$dW = PdV = nRdT$ (isobaric process)
$dU : dQ : dW : C _{ v }: C _{ p }: R$
$=\frac{5 R }{2}: \frac{7 R }{2}: R =5: 7: 2$