Question

In thermodynamic process pressure of a fixed mass of gas is changed in such a manner that the gas releases $30$ joule of heat and $18$ joule of work was done on the gas. If the initial internal energy of the gas was $60$ joule, then, the final internal energy will be:

• A. $32joule$
• B. $48joule$
• C. $72joule$
• D. $96joule$

Answer 1

The correct option is B $48joule$

$\text{Given:-}$ $Q_{release}=30J$

Work done = 18 J

$\text{Solution:-}$

It is given that, initial internal energy $U_i=60J$ gas releases 30 J of heat and 18 J of work is done on the gas

$\Rightarrow$ And the whole, the gas loses 12 J energy

$\Rightarrow$ its internal energy will decreases by 12 J, hence final internal energy is:

$U_f=60-12$

$U_f=48J$

$\text{Hence the correct option B}$