Power
Physics ⇒ Mechanics
Power starts at 8 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Power.
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See sample questions for grade 9
Describe a real-life example where high power is needed but not necessarily a large amount of work.
Describe how you would measure the power output of a person climbing stairs.
Explain the difference between work and power.
Explain why power is important in designing machines and engines.
A 100 W light bulb is left on for 2 hours. How much energy does it use in joules?
A 1200 W microwave runs for 3 minutes. How much energy does it use in kilojoules?
A 40 W device is used for 30 minutes. How much energy does it use in joules?
A 60 kg person runs up a 5 m high hill in 10 seconds. What is the average power output? (Take g = 10 m/s²)
Which of the following appliances uses the most power? (1) 60 W bulb (2) 100 W fan (3) 1500 W heater (4) 500 W refrigerator
Which of the following best describes average power? (1) Total work divided by total time (2) Maximum work done at any instant (3) Work done per unit distance (4) Force divided by time
Which of the following is a correct statement about power? (1) Power is always constant. (2) Power can change depending on how quickly work is done. (3) Power is measured in joules. (4) Power is a vector quantity.
Which of the following is equivalent to 1 watt? (1) 1 J/s (2) 1 N·m/s (3) Both (1) and (2) (4) 1 N/s
Fill in the blank: 1 horsepower is equal to approximately ______ watts.
Fill in the blank: Power is a measure of how ______ energy is transferred or converted.
Fill in the blank: The power developed by a force F moving an object at velocity v is ______.
Fill in the blank: The rate of doing work is called ______.
True or False: If no work is done, the power is zero.
True or False: Power can be increased by doing the same amount of work in less time.
True or False: Power can be negative if work is done in the opposite direction of motion.
True or False: Power is a scalar quantity.
