Question

What will be work done in supplying $400\text{calories}$ of heat to a system?

• A. $1672\text{J}$
• B. $836\text{J}$
• C. $418\text{J}$
• D. $209\text{J}$

Answer 1

The correct option is A $1672\text{J}$

Given,
Heat supplied $\left(H\right)=400\text{calories}$
Let the work done in supplying heat to the system be $W$ (say)
We know that,
$W=JH$
where, $J$ is the mechanical equivalent of heat which has a value of $4.18\text{joules /calorie}$
$\therefore$ $W=4.18\times 400=1672\text{J}$
Thus, option (a) is the correct answer.