Question

if a carnot engine functions at source temperature 127 and sink temperature 87 what is its efficiency

Answer 1

The efficiency(n) of a Carnot Engine is given by 1 - Temperature of Sink/Temperature of Source

Hence n= 1-87/127

n= 1-0.68

n= 0.32.

Answer 2

Question : If a carnot engine functions at source temperature 127°C and sink temperature 87°C what is its efficiency?

Introduction :

According to Second law of thermodynamics, No heat engine can have 100% efficiency.

A Scientist named, Carnot gave the statement, no heat engine has more efficiency than the reversible heat engine working between the given temperatures.

So, Carnot heat engine is a ideal heat engine with the most efficiency possible between given temperatures of sink and source.

Efficiency of carnot heat engine working between Temperatures T1, T2 is given by,

$\eta = 1 - \frac{T_{2}}{T_{1}}$

Solution

Given,

Temperature of the source T1 = 127 °C = 127 + 273 = 400 K

Temperature of the sink T2 = 87°C = 360K

Now,

$\sf \: Efficiency(\eta \: ) \\ = 1 - \frac{360}{400} \\ = 1 - \frac{9}{10} = \frac{1}{10}$

Thus, The efficiency of carnot engine working between 127°, 87°C is 1/10 or 10%.