Question

An engine is working between the temperatures 30 K
and 300 K. What is its
efficiency?
10%
47%
50%
90%​

Answer 1

Answer:

i think the answer would be 47%

because the efficiency of 300 is 40% so if 300k = 40% then 30k = 7% so the answer is 47%

Answer 2

Given:

• Temperature of source = 300 K
• Temperature of sink = 30 K

To find:

• Efficiency of engine ?

Calculation:

• The efficiency of any thermodynamics engine is given as :

$\boxed{\eta =1 - \dfrac{T_{sink}}{T_{source}} }$

Putting the values in SI UNITS:

$\implies\eta =1 - \dfrac{30}{300}$

$\implies\eta =1 - \dfrac{1}{10}$

$\implies\eta =1 - 0.1$

$\implies\eta =0.9$

In percentage values :

$\implies\eta = \dfrac{0.9}{1} \times 100\%$

$\implies\eta = 90\%$

So, efficiency of the engine is 90%.