Question

One of the most efficient engines ever developed operates between 2100 K and 700 K. Its actual efficiency is 40%. What percentage of its maximum possible efficiency is this?

Solution

Correct option is

60%

 

 

                   

Actual efficiency is 40% which is 60% of the theoretical efficiency.

SIMILAR QUESTIONS

Q1

The temperatures of inside and outside of a refrigerator are 273 K and 303 K respectively. Assuming that the refrigerator cycle is reversible, for every joule of work done, the heat delivered to the surroundings will be nearly:

Q2

In a thermodynamic process, pressure of a fixed mass of a gas is changed in such a manner that the gas releases 20 J of heat and 8 J of work is done on the gas. If initial internal energy of the gas was 30 J, what will be the final internal energy?

Q3

 

An ideal gas is taken through a cyclic thermo-dynamical process through four steps. The amounts of heat involved in these steps are:

    respectively. The corresponding works involved are:  respectively. The value of W4 is:

Q4

When an ideal diatomic gas is heated at constant pressure fraction of the heat energy supplied which increases the internal energy of the gas is:

Q5

70 calories of heat are required to raise the temperature of 2 moles of an ideal gas at constant pressure from 30oC to 35oC. The amount of heat required to raise the temperature of the same gas through same range (30oC to 35oC) at constant volume is:

Q6

A motor-car tyre has a pressure of 2 atmosphere at 27oC. It suddenly bursts. If (Cp/Cv) = 1.4 for air, find the resulting temperature:

Q7

Find the  amount of work done to increase the  temperature of one mole of ideal gas by 30oC, if it is expanding under the condition  (R = 8.31 J/mol-K):

Q8

For an adiabatic expansion of a perfect gas, the value of  is equal to:

Q9

In an adiabatic expansion of a gas, the product of pressure and volume:

Q10

In an adiabatic change, the pressure P and temperature  of a diatomic gas are related by the relation   where equals: