Question

For path ABC, Heat given to the system is $60\mathrm{J}$ and work done by the system is $30\mathrm{J}$. For path ADC, work done by the system is $10\mathrm{J}$. The heat given to the system for path ADC is

• A. $100\mathrm{J}$
• B. $80\mathrm{J}$
• C. $40\mathrm{J}$
• D. $60\mathrm{J}$

Answer 1

The correct option is C

$40\mathrm{J}$

Step 1: Given data

Heat $=60\mathrm{J}$

Work $=30\mathrm{J}$

In ABC

$$\begin{gathered} ∆\mathrm{U}=60-30 \\ =30 \end{gathered}$$

Step 2: Find the heat

In ADC

$∆\mathrm{Q}=∆\mathrm{U}+∆\mathrm{W}$

$$\begin{gathered} ∆\mathrm{Q}=30+10 \\ =40\mathrm{J} \end{gathered}$$

Therefore, heat given to the system for path ADC is $40\mathrm{J}$.

Hence, option C is correct.