A Heat Engine Operating Between the Temperatures T₁ and T₂

Multiple Choice

A heat engine operating between the temperatures T₁ and T₂ takes in Q₁ calories at temperature T₁ and gives up Q₂ calories at temperature T₂.The efficiency of this heat engine is

A) (Q₁ - Q₂) /Q₂
B) (Q₁ - Q₂) /Q₁
C) (T₂ - T₁) /T₂
D) Q₂/(Q₁ - Q₂)
E) T₁/(T₁ - T₂)