A wire of resistance 9 ohm is bent into a circle. It is then connected, to a battery of 12V, using conducting wires at two points such that: one arc is 3 times longer than the other. What is the current flowing through the circuit?

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.