Second Law of Thermodynamics.

It is impossible to produce a heat engine, whose sole effect is to absorb energy in the form of heat from a heat source and produce an equal amount of work. This statement is

a. Kelvin-Planck statement
b. Clausius statement
c. Third law of thermodynamics
d. none of the above

Correct Answer : a. Kelvin-Planck statement

Explanation :

In heat engine, net work output is always less than heat input. Hence total heat energy transferred to the heat engine can not be converted completely into work output. Therefore efficiency of a heat engine is always less that 100%. Thus, it is impossible to produce a heat engine, whose sole effect is to absorb energy in the form of heat from a heat source and produce an equal amount of work. This is a Kelvin-Planck statement.