Question 550: Thermodynamics & KTG

Question

A carnot engine takes $$3 	imes {10^6}$$ cal. of heat from a reservoir at $${627^ \circ }C,$$ and gives it to a sink at $${27^ \circ }C$$. The work done by the engine is

Accepted Answer

$$\eta  = 1 - {{{T_2}} \over {{T_1}}}$$
$$ = 1 - {{\left( {273 + 27} ight)} \over {\left( {273 + 627} ight)}}$$
$$ = 1 - {{300} \over {900}}$$
$$ = 1 - {1 \over 3} = {2 \over 3}$$
But $$\eta  = {W \over Q}$$
$$	herefore$$ $${W \over Q} = {2 \over 3} \Rightarrow W$$
$$ = {2 \over 3} 	imes Q$$
$$ = {2 \over 3} 	imes 3 	imes {10^6}$$
$$ = 2 	imes {10^6}cal$$
$$ = 2 	imes {10^6} 	imes 4.2\,J$$
$$ = 8.4 	imes {10^6}J$$

Answer

$$4.2 	imes {10^6}J$$

Answer

$$8.4 	imes {10^6}J$$

Answer

$$16.8 	imes {10^6}J$$

Answer

zero

Thermodynamics & KTG

A carnot engine takes $3 \times {10^6} cal. of heat from a reservoir at {627^ \circ }C, and gives it to a sink at {27^ \circ }C$. The work done by the engine is

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