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प्रश्न
Write the energy transformations which take place in an electric bulb (or electric lamp).
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उत्तर
An electric bulb converts electrical energy into light energy. Electrical energy causes the filament in the bulb to become white-hot and give out light. So, in an electric bulb, the electrical energy is first converted into heat energy and then to light energy. This energy transformation can be written as,
Electrical energy → Heat energy → Light
संबंधित प्रश्न
In what way does the temperature of water at the bottom of a waterfall differ from the temperature at the top? Explain the reason.
Show that the sum of kinetic energy and potential energy (i.e., total mechanical energy) is always conserved in the case of a freely falling body under gravity (with air resistance neglected) from a height h by finding it when
- The body is at the top.
- the body has fallen a distance x.
- the body has reached the ground.
Is energy a vector quantity?
State whether the object possess kinetic energy, potential energy, or both :
A bird running on the ground ____________.
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Water stored in the reservoir of a dam __________.
Fill in the blank with suitable word :
The ability of a body to do work is called __________. The ability of a body to do work because of its motion is called __________.
Fill in the blank with suitable word :
The sum of the potential and kinetic energies of a body is called __________ energy.
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Name the device or machine which convert :
Mechanical energy into electrical energy.
Name the device or machine which convert :
Chemical energy into electrical energy.
Fill in the blanks with suitable words:
When a ball is thrown upwards, ___________ energy is transformed into ___________ energy.
What kind of energy transformations take place at a coal-based thermal power station?
How much electrical energy in joules does a 100 watt lamp consume : in 1 second?
How much electric energy in kWh is consumed by an electrical appliance of 1000 watts when it is switched on for 60 minutes?
Name the energy transfers which occur when there is a picture on a television screen.
A ball falls to the ground as shown below :
What is the potential energy of ball at B?
A ball falls to the ground as shown below :
Which law you have made use of in answering this question?
The device which converts mechanical energy into energy which runs our microwave oven is :
A body of mass 10 kg falls from a height of 20 m to 8 m. Calculate:
- the loss in potential energy of the body, and
- the total energy possessed by the body at any instant? (Take g = 10 m s-2)
