Advertisements
Advertisements
Question
Name the commercial unit of measurement of energy.
Advertisements
Solution
Kilowatt- hour (kWh) is the commercial unit of measurement of energy.
APPEARS IN
RELATED QUESTIONS
Fill in the blank
Cooking gas converts _______ energy into heat energy.
What is potential energy ? State its unit.
Match the following:
| Column A | Column B |
| (a) Needle | (1) class II lever |
| (b) Doorknob | (2) inclined plane |
| (c) Ramp | (3) Class I lever |
| (d) Lemon crusher | (4) Wheel and axle |
| (e) Seesaw | (5) wedge |
Answer the following in short.
What do you understand by the term efficiency of a machine’?
How many joules are there in one kilowatt-hour?
Name the quantity whose unit is :
(a) kilowatt
(b) kilowatt-hour
What is the common name of '1 kWh' of electrical energy?
Derive the relation between commercial unit of energy (kWh) and SI unit of energy (joule).
- Take two aluminium channels of different lengths.
- Place the lower ends of the channels on the floor and hold their upper ends at the same height.
- Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.
- At the moment of releasing the balls, which energy do the balls have?
- As the balls roll down which energy is converted into which other form of energy?
- Why do the balls cover the same distance on rolling down?
Note: The question is wrong. It should be "Why do the balls cover the same distance after rolling down"? - What is the form of the eventual total energy of the balls?
- Which law related to energy does the above activity demonstrate? Explain.
We make useful objects from a variety of substances. Another use of substances is that we get energy from some of them.
When we have run a long distance, we feel tired. We have to stop. Why is that?
