Why is the efficiency of a carnot's engine not 100%?

Find the efficiency of a carnot's engine working between 500K and 300K

Find the efficiency of a carnot's engine that works between the temperature 427 degree C and 27 degree C of the source and the sink respectively . If the 140 calories of heat are absorbed from the source by the engine in one cycle calculate the heat rejected into the sink .

How can the efficiency of a reversible engine be 100%?

On what does the efficiency of a heat engine depends ?

state the factors upon which the efficiency of a heat engine depends .

Calculate the efficiency of a Canot engine operating between 450 K and 300K.

A steam engine delivers 5.4 xx 10^8 J of work per minute and services 3.6 XX 10^8 J of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?

Describe heat engine. Define efficieny of heat engine. Mention two reasons for which the efficiency of a heat engine becomes low.

An ideal heat engine takes in heat at 1520K and rejects heat at 380K . What is the efficiency of that engine ?

The efficiency of a Carnot engine is frac(1)(6) when temperature if the sink decrease by 65 K its efficiency becomes frac(1)(3) . Calculate the initial and final temperature.