Advertisements
Advertisements
प्रश्न
Answer the following in a word or two or in a sentence.
Write the formula for calculating the efficiency of a machine.
उत्तर
Efficiency =`"Output energy"/"Input energy"`
The percentage value of efficiency of a machine is calculated as
Efficiency =`" Output energy"/" Input energy"`× 100 %
APPEARS IN
संबंधित प्रश्न
Select the correct alternatives
When we rub our hands
Select the correct alternatives
The correct statement is
What is energy?
Answer the following in short.
What do you understand by the term efficiency of a machine’?
Give a reason for the following.
The efficiency of a machine is always less than 100%.
What is the common name of '1 kWh' of electrical 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.
If the energy of a ball falling from a height of 10 metres is reduced by 40%, how high will it rebound?
What energy transfer happen in a car engine?
When a body falls freely towards the earth, then its total energy
