Quiz for Heat engines

Q1: What is the efficiency of a Carnot engine operating between 500 K and 300 K?

A. 40% B. 50% C. 60% D. 70%

Q2: Which law of thermodynamics governs the working of a heat engine?

A. Zeroth law B. First law C. Second law D. Third law

Q3: A perfect heat engine absorbs 100 J of heat and does 40 J of work. What is its efficiency?

A. 40% B. 60% C. 70% D. 80%

Q4: Which device converts heat into mechanical energy?

A. Refrigerator B. Air Conditioner C. Heat Engine D. Fan

Q5: Which of the following is an example of a heat engine?

A. Steam turbine B. Electric motor C. Battery D. Transformer

Q6: What is the maximum efficiency of a Carnot engine?

A. 100% B. 75% C. Depends on temperatures D. 0%

Q7: In a Carnot engine, efficiency increases if:

A. Source temperature decreases B. Sink temperature increases C. Sink temperature decreases D. No change in temperature

Q8: If the efficiency of an engine is 25%, what is the ratio of heat rejected to heat absorbed?

A. 3:1 B. 1:3 C. 1:4 D. 4:1

Q9: What is the unit of efficiency?

A. Joule B. Watt C. Percentage D. No unit

Q10: A heat engine rejects 70 J of heat and does 30 J of work. What is the input heat?

A. 100 J B. 70 J C. 30 J D. 40 J

Q11: Which cycle is used in a gasoline engine?

A. Otto cycle B. Diesel cycle C. Carnot cycle D. Rankine cycle

Q12: Which of these is not an assumption of Carnot engine?

A. Working substance is ideal gas B. No friction C. Heat transfer is instantaneous D. All processes are reversible

Q13: Which process is not involved in Carnot cycle?

A. Isothermal expansion B. Adiabatic expansion C. Isobaric compression D. Isothermal compression

Q14: In a Carnot engine, heat is absorbed at 400 K and rejected at 300 K. What is the efficiency?

A. 25% B. 33.3% C. 50% D. 75%

Q15: Which of the following is a reversible process?

A. Burning of fuel B. Free expansion of gas C. Frictional motion D. Isothermal expansion in Carnot cycle

Q16: Heat engines convert:

A. Mechanical energy to heat B. Chemical energy to heat C. Heat to mechanical energy D. Electrical energy to heat

Q17: If no heat is rejected by the engine, its efficiency is:

A. Zero B. 100% C. 50% D. Undefined

Q18: Which component of a heat engine absorbs heat?

A. Condenser B. Sink C. Source D. Cylinder

Q19: The device used to measure mechanical work done by a heat engine is:

A. Calorimeter B. Manometer C. Dynamometer D. Voltmeter