Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

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

Iron glows in red colour when it is heated to very high temperature because:

  1. Heat we supply consumes red colour at high temperature

  2. Mechanical energy is being converted into heat energy

  3. <span>Light energy is being converted into heat energy</span>

  4. Heat energy is being converted into light energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Iron glows in red colour when it is heated to very high temperature because heat being a form of energy can be transformed into other forms of energy.

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

A moving coin hits another coin and sets it into motion.In this case energy from the moving coin is ---- to the other coin:

  1. Flown

  2. Taken

  3. Not transferred

  4. Transferred
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The moving coin has kinetic energy initially, after hitting the other coin it transfers its kinetic energy to the other coin and sets it in motion.(In reality some part of energy is also lost as heat energy)

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

When a stone is thrown upwards:

  1. Kinetic energy increases and Potential energy decreases

  2. both Kinetic energy and Potential energy increase

  3. Kinetic energy decreases and Potential energy increases

  4. both remain constant
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a stone is thrown upwards, its velocity decreases and height increases. 

$K.E. = \dfrac{1}{2}{ mv }^{ 2 }$
$P.E. = mgh$
Thus, its kinetic energy decreases and potential energy increases.

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

Which of the following statement is NOT true?

  1. State of rest of a body is same as the state of zero speed

  2. Human body converts chemical energy into muscular energy

  3. Water in river flows down due to its kinetic energy

  4. Liquids exert pressure on the walls&nbsp;of the container
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Option C is not correct because river flows down due to its gravitational potential energy.

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

In steam engine:

  1. Mechanical energy is converted to heat energy

  2. Heat energy is converted to mechanical energy

  3. Heat energy is converted to electrical energy

  4. Heat energy is converted to chemical energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Heat is used to generate steam which moves the pistons and thereby converting heat energy to mechanical energy.

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.