Tag: different forms of energy

Questions Related to different forms of energy

Burning of a meteorite in the earth's atmosphere is an example of change of :

  1. heat energy into kinetic energy

  2. kinetic energy into heat energy

  3. kinetic energy into potential energy

  4. potential energy into heat energy


Correct Option: B
Explanation:

A meteorite has both potential and kinetic energy before entering earth's atmosphere. As it enters and fall towards the surface of earth, frictional heating occurs which is caused by collision with the molecules in the atmosphere which reduces its velocity. Hence the kinetic energy decreases, which is converted into heat energy. Potential energy is continuously decreasing being converted to kinetic energy.

When fuels are burnt, chemical energy changes into:

  1. kinetic and potential energy

  2. solar energy

  3. heat and light energy

  4. nuclear energy


Correct Option: C
Explanation:

Fuels contain chemical energy stored in them. When fuels are burnt, the chemical energy changes into heat and light energy.

A ball is placed on a compressed spring. On releasing the spring, the ball flies away. Then which of the following is true?

  1. The ball creates its own kinetic energy

  2. Elastic potential energy of the spring is destroyed and kinetic energy of the ball is created

  3. Potential energy of the ball is destroyed and kinetic energy of the spring is created

  4. Elastic potential energy of the spring gets converted into kinetic energy of the ball


Correct Option: D
Explanation:

Work is done on the spring to compress it. This work is stored in the spring in the form of its elastic potential energy. When the spring is released, its elastic potential energy gets transformed into the kinetic energy of the ball and the ball flies away.

Which of the following devices converts electrical energy into heat energy?

  1. A dynamo

  2. An electric iron

  3. A loud speaker

  4. A thermocouple


Correct Option: B
Explanation:

An electric iron converts electrical energy into heat energy.

Buming of a meteorite in the Earth's atmosphere is an example of change of:

  1. heat energy into kinetic energy

  2. kinetic energy into heat energy

  3. kinetic energy into potential energy

  4. potential energy into heat energy


Correct Option: B
Explanation:

when meteorite falls its potential energy is converting into kinetic energy and when it enters earth atmosphere due to air friction its kinetic energy is reduced but potential energy is also decreasing as its height is decreasing , so we can conclude that its first potential energy converts to kinetic energy and then kinetic energy converts to heat energy.

so best possible answer is option B.

A generator is an arrangement which converts _________ energy into _________ energy.

  1. mechanical, electrical

  2. mechanical, chemical

  3. potential, electrical

  4. electrical, chemical


Correct Option: A
Explanation:

 A generator converts mechanical energy into electrical energy.  Generator works due to this because of electromagnetic induction generated due to this conversion of energy. Also magnetic field is produced which results in generation of voltage that helps the generator to function.

A motor converts:

  1. electrical energy into mechanical energy

  2. mechanical energy into electrical energy

  3. electrical energy into heat energy

  4. heat energy into electrical energy


Correct Option: A
Explanation:

A motor converts electrical energy into mechanical energy.

In which of the following chemical energy is converted into heat energy?

  1. Heater

  2. Cooler

  3. Motor

  4. Candle


Correct Option: D

During photosynthesis, green plants convert:

  1. chemical energy into light energy

  2. light energy into chemical energy

  3. light energy into mechanical energy

  4. light energy into muscular energy


Correct Option: B
Explanation:

During photosynthesis, green plants convert light energy into chemical energy stored in the form of food.

Which of the following devices convert light energy into electrical energy?

  1. An electric bulb

  2. A photocell

  3. A microphone

  4. A dynamo


Correct Option: B
Explanation:

A photocell gives out electric current when light is incident on it. So, it converts light energy into electrical energy.