Advertisements
Advertisements
प्रश्न
Derive the relation between commercial unit of energy (kWh) and SI unit of energy (joule).
Advertisements
उत्तर
We can establish a relation between kilowatt-hour (kWh) and Joule (J) as –
1 kilowatt-hour = 1 kilowatt for 1 hour
= 1000 watt for 1 hour
But,
`1 "watt" = (1 "Joule")/(1 "s")`
So ,
1 kilowatt - hour = 1000 `"Joules"/"second"` for 1 hour
= `1000 "Joules"/"seconds" 60 xx 60 "seconds"`
= `3.6 xx 10^6` J
APPEARS IN
संबंधित प्रश्न
Write true or false of the following statement.
Potential energy changes into kinetic energy when it is put to use
State two factors on which the potential energy of a body at a certain height above the ground depends.
What is energy?
Give a reason for the following.
The efficiency of a machine is always less than 100%.
Name two units of power bigger than watt.
- 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.
Can you tell?
What should be taken into account for measuring work?
We make useful objects from a variety of substances. Another use of substances is that we get energy from some of them.
There is a car. Its tank is full of fuel but it does not move. Why is that?
When a body falls freely towards the earth, then its total energy
The weight of a person on planet A is about half that on the earth. He can jump up to 0.4 m in height on the surface of the earth. How high he can jump on planet A?
