The efficiency of a heat engine working between the freezing point and the boiling point of water is near to:
Correct answer: B. 25%
- A. 50%
- B. 25%
- C. 12.5%
- D. 6.25%
Explanation
Boiling point of water= 100° =373KFreezing point of water=0° = 273KThe formula for efficiency; =1-TCold/Thotx100 = 1- 273/373x100 =26.80% ≈25%NOTE: make sure the temperature values being used in the formula are in Kelvin.In the numerator, we always take the cold body's temperature.In the denominator, we always take the hot body's temperature.
Last updated
About Energy Losses and Efficiency
Efficiency compares useful output energy or power with the total input, usually expressed as a percentage. The topic covers energy losses through friction, heating, resistance and sound, along with power ratings and Sankey diagrams. Efficiency is not the same as conservation of energy, because lost energy is transferred rather than destroyed.
Practise Work and Energy
748 free Work and Energy MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A machine takes in 500 J and delivers 350 J of useful output. Its efficiency is
A machine takes in 500 J and delivers 400 J of useful output. Its efficiency is
A reversible Carnot engine converts 1/6th of heat into input work. When the temperature of the sink is reduced by 62˚C and the efficiency is doubled then the temperature of the source and sink is:
Biomass can be converted into fuels by____________________?
Earth receives large amount of energy directly from: