Advertisements
Advertisements
Question
Answer the following in a word or two or in a sentence.
Write the formula for calculating the efficiency of a machine.
Advertisements
Solution
Efficiency =`"Output energy"/"Input energy"`
The percentage value of efficiency of a machine is calculated as
Efficiency =`" Output energy"/" Input energy"`× 100 %
APPEARS IN
RELATED QUESTIONS
Write true or false of the following statement.
In an electric fan, electrical energy changes into the mechanical energy.
Select the correct alternatives
When we rub our hands
What do you mean by conservation of mechanical energy? State the condition when does it hold.
Give a reason for the following.
The efficiency of a machine is always less than 100%.
Name the commercial unit of measurement of energy.
- 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.
There is a car. Its tank is full of fuel but it does not move. Why is that?
Observe the picture and put a tick (✓) if work is done and put a cross (x) if work is not done.
 |
 |
 |
 |
 |
 |
Find out the form of energy possessed by the following thing.
A rock on the top of a hill
Write the type of energy.
