In a heat engine, qh and qc represents high temperature substance and low temperature substance respectively. which of the following expressions is correct for the efficiency of the heat engine?

The efficiency of a heat engine is given by the expression

The efficiency of a heat engine is the ratio of the work done by the engine to the heat given as the input to the engine.

The heat engine absorbs Q h from the hot reservoir , performs a work W on the absorbed heat and rejects Qc to the cold reservoir.

Therefore, the work done  is given by,

Thus the efficiency is given by,

6 cos 34, 6 sin 34 trig