# Work Force and Energy MCQs

#### Work done in raising a box on to a platform depends on ____.

Correct! Wrong!

Work done in raising a box on to a platform depends on the height to which it is raised. When a body is raised to a height then work done is equal to the potential energy.

#### To describe work done on an object, we require: The magnitude of the net force acting on the object, its initial position and its final position.

Correct! Wrong!

The magnitude of the net force acting on the object, its initial position and its final position.

#### A bird flying in the sky has only kinetic energy.

Correct! Wrong!

Flying bird has both velocity as well as altitude so it has both KE and PE.

#### The unit Nm is equivalent to ____.

Correct! Wrong!

Unit Nm is equivalent to J.

#### When the pendulum bob is in the mean position, total energy will be minimum.

Correct! Wrong!

When the pendulum bob is in the mean position, the total energy will remain unchanged. Total energy is the sum of KE and PE. At mean position, the KE is maximum and PE is zero. Hence, the total energy remains unchanged.

#### If the displacement-time graph of a particle represents a line parallel to the time-axis, then the velocity of the particle is ____.

Correct! Wrong!

As the graph representing a line parallel to the time-axis, the velocity of the particle is zero.

#### A labour carrying a suitcase on his head moves from rest on a horizontal road to another point and finally comes to rest. Then, the work done by gravity is ____.

Correct! Wrong!

work done is zero.

#### Work done by force acting on an object is equal to the magnitude of the force multiplied by the displacement of the object in the direction of the force.

Correct! Wrong!

Work done by force acting on an object is equal to the magnitude of the force multiplied by the displacement of the object in the direction of the force.

#### In the SI system, the unit of potential energy, PE, is ____.

Correct! Wrong!

In the SI system, the unit of potential energy, PE, is joule.

#### No work is said to be done, when an object moves at an angle of ____ with the direction of the force.

Correct! Wrong!

Work done is zero.

#### Work done on a body is a vector quantity.

Correct! Wrong!

Work done on a body is a scalar quantity.

#### A watch spring in the wounded position has both kinetic as well as potential energies.

Correct! Wrong!

Potential energy is stored in the spring by change in configuration of the body.

#### When force is applied on a body, work done by it is always positive.

Correct! Wrong!

When force is applied on a body, work done by it can be positive, negative or zero.

#### When a body is whirled in a circle, then work done on it by the tension in the string is ____.

Correct! Wrong!

Work done by the tension in the string is zero.

#### Sound energy is converted into electrical energy by ____.

Correct! Wrong!

Sound energy is converted into electrical energy by a microphone.

#### Work done by a centripetal force ____.

Correct! Wrong!

work done by the centripetal force is always zero.

#### A body in motion comes to rest when force is applied on it. The work done by the force on the body is ____.

Correct! Wrong!

Force and displacements are in opposite direction. A body in motion comes to rest when force is applied on it. Hence, the work done by the force on the body is negative.

#### Work done by the gravitational force on a body is ____.

Correct! Wrong!

When a body is carried along the direction of the gravitational force, the work done is positive and vice-versa. When the displacement is made perpendicular to the direction of the gravitational force, the work done is zero.

#### Work is measured as a product of ____.

Correct! Wrong!

Work done is given by the product of force and displacement, represented by, Work = force × displacement.

#### When a body is released from a height the kinetic energy of the body is gradually changed into potential energy.

Correct! Wrong!

When a body is released from a height the potential energy of the body is gradually changed into kinetic energy. In this case total mechanical energy is conserved or constant.

#### When the force applied and the displacement of the body is inclined at 90°, with each other, the work done is ____.

Correct! Wrong!

Work done is zero.

#### An object can be at rest as well as in motion at the same time.

Correct! Wrong!

An object can be at rest relative to one object as well as in motion at the same time relative to another object.

#### Work done by the gravitational pull of the Sun on the Earth is maximum in the month of July.

Correct! Wrong!

The work done by the gravitational pull of the Sun on the Earth is zero.

#### Which of the following is a wrong statement regarding the graphical representation of motion of an object?

Correct! Wrong!

By representing the motion of an object graphically, we can: Infer the nature of motion Determine its position at any intermediate interval. Calculate its acceleration, displacement, velocity, etc. at any instant and Derive equations of motion

Work Force and Energy MCQs
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