A) prevent radiation
B) find ideal sources
C) reach absolute zero temperature
D) eliminate friction
Correct Answer: C
Solution :
The efficiency of Carnot engine is \[\eta =1-\frac{{{T}_{2}}}{{{T}_{1}}}\] where, \[{{T}_{1}}\] is the temperature of the source and \[{{T}_{2}}\] that of sink. Since, \[\frac{{{T}_{2}}}{{{T}_{1}}}=\frac{{{Q}_{2}}}{{{Q}_{1}}}\] So, \[\eta =1-\frac{{{Q}_{2}}}{{{Q}_{1}}}\] To obtain 100% efficiency (i.e., \[\eta =1\]), \[{{Q}_{2}}\] must be zero i.e., if a sink at absolute zero would be available, all the heat taken from the source would have been converted into work. The temperature of sink means a negative temperature on the absolute scale at which the efficiency of engine is greater than unity. This would be a violation of the 2nd law of thermodynamics. Hence, a negative temperature on the absolute scale is impossible. Hence, we cannot reach absolute zero temperature.
You need to login to perform this action.
You will be redirected in
3 sec
