Question

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

• A. Change in Internal Energy of Gas - Work done by Gas, $45J-0J$
• B. Change in Internal Energy of Gas - Work done by Gas, $90J--45J$
• C. Change in Internal Energy of Gas - Work done by Gas, $-45J-90J$
• D. Change in Internal Energy of Gas - Work done by Gas, $0J-45J$
• E. Change in Internal Energy of Gas - Work done by Gas, $22.5J-22.5J$

Answer 1

The correct option is D Change in Internal Energy of Gas - Work done by Gas, $0J-45J$

Given : $Q=45$ $J$

Change in internal energy of the gas in a cyclic process is zero i.e $\Delta U=0$

Using 1st law, $Q=\Delta U+W$

$\therefore$ $45=0+W$ $⟹W=45$ $J$