Question

When an ideal diatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas, is-

• A. $\frac { 2 } { 5 }$
• B. $\frac { 3 } { 5 }$
• C. $\frac { 3 } { 7 }$
• D. $\frac { 5 } { 7 }$

Answer 1

Answer: (D)

$\frac { 5 } { 7 }$

Answer 2

(DU) = nC_VDT , (DQ)_P = nC_P.DT

$\frac { \Delta U } { ( \Delta Q ) _ { P } } = \frac { C _ { V } } { C _ { P } } = \frac { 1 } { \gamma } = \frac { 5 } { 7 }$