Question

During a cyclic thermodynamic process, a gas absorbs 45 J of heat.
Which table correctly describes the change in internal energy in the gas and work done by the gas during this cycle?

• A. $45$ $J$
• B. $54$ $J$
• C. $40$ $J$
• D. $50$ $J$
• E. $60$ $J$

Answer 1

The correct option is A $45$ $J$

As heat is absorbed by the gas, $⟹$ $Q=+45$ J

Change in internal energy of the gas during one cycle is zero i.e $\Delta U=0$ J

From 1st law of thermodynamics : $Q=\Delta U+W$

$\therefore$ $45=0+W$ $⟹W=+45$ J

Thus the work done by the gas is $45$ J.