Tag: the essence of change

Quizzes (5) Questions (143)

Questions Related to the essence of change

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

The device / machine which converts chemical energy into electrical energy is

  1. Electric bulb

  2. Electric motor

  3. Battery

  4. Solar cell
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Option A: Electrical bulb converts electrical energy into heat.

Option B: electrical motor converts electrical energy in mechanical energy.
Option C : battery converts chemical emergy into electrical energy.
Option D: solar cell converts light (using photons) into electrical energy.
So best possible answer is option C.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

Which of the following statements is correct?

  1. Kinetic energy of a system can be changed without changing the momentum

  2. Kinetic energy of a system cannot be changed without changing its momentum

  3. Momentum of a system cannot be changed without changing its kinetic energy

  4. A system cannot have energy without having momentum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A

Momentum is a vector quantity while K.E is a scalar quantity ,we can change velocity in such a way momentum remains same but K.E changes .

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

A solar water heater converts

  1. Light energy into heat energy

  2. Heat energy into light energy

  3. Chemical energy into heat energy

  4. Light energy into electrical energy
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Solar heater absorbs light, and thus photons of light are absorbed and the energy contained in them is converted to heat energy, which raises the temperature of water flowing slowly in contact with the plate and thus heat energy is transfered from plate to water.

Hence a solar heater converts light energy into heat energy.
Option A.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

The temperature of water at the bottom of a waterfall is higher than that of the water at the top, because:

  1. falling water absorbs heat from the sun.

  2. kinetic energy of the falling water is converted into heat.

  3. water at the bottom has greater potential energy.

  4. the rocks on the river bed give out heat.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When water is flowing it posses some kinetic energy and also posses some potential energy wrt to the lower level of the waterfall.

When water fall from higher level its potential energy gets converted to kinetic energy and when water reaches to lower level some part of its kinetic energy gets converted to sound energy amd some to heat energy.
So best possible option is option B.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

Multiple choice physics the essence of change different forms of energy energy conversions energy transformations and energy transfers

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.