Question:
A Carnot's engine working between $400 \mathrm{~K}$ and $800 \mathrm{~K}$ has a work output of $1200 \mathrm{~J}$ per cycle.
The amount of heat energy supplied to the engine from the source in each cycle is :
Correct Option: , 4
Solution:
(4)
$\eta=\frac{T_{2}}{T_{1}}=\frac{Q_{2}}{Q_{1}}=\frac{Q_{1}-W}{Q_{1}} \quad\left(\because W=Q_{1}-Q_{2}\right)$
$\frac{400}{800}=1-\frac{W}{Q_{1}}$
$\frac{W}{Q_{1}}=1-\frac{1}{2}=\frac{1}{2}$
$Q_{1}=2 W=2400 \mathrm{~J}$