1. Work is related to area in a PV diagram. The work done by a system in an
expansion is equal to the area under the curve on a PV diagram.
In a cyclic process, the work done by a system, is
equal to the area enclosed by the PV diagram which represents the process.
The work done in the cyclic process in which a system passes through states
A, B, C, D and returns to state A is given by the area enclosed by the curve
ABCDA.
2. The Efficiency of a Heat Engine
The efficiency of a heat engine (n) is defined as
n =


The Carnot cycle
is the most efficient cycle for a heat engine. It operates between a source
of heat at temperature T_{2} and a sink at temperature T_{1.}
Its efficiency is given by
n =


3. Conversion of Temperature from Celcius to Farenheit Scale
T_{F} =


T_{C} + 32

