MCQs on Work Power and Energy

Bookmark added to your notes.
View Notes
×

What are Work, Energy, and Power?

The terms Work, energy, and power are the most commonly used ones in Physics.

Work can be said to be done when a force produces motion. For example, when a person climbs the house or office stairs, work is said to be done because he is moving against the force of gravity.

Work is measured by the product of force and displacement of the body along the direction of the force. It belongs to a scalar quantity, and its SI unit is the joule.

Energy is the capacity of doing work by a body. It is a scalar quantity, and because of this reason, it has only magnitude, but no direction and its unit is the joule. The energy required to perform 1 joule of work is called 1-joule energy.

Power can be explained as the rate of doing work. It is also a scalar quantity.

There are many work power energy questions. Let us discuss a few among NEET UG physics work energy and power.


Importance of MCQs

In general, the Multiple Choice Questions (MCQs) are recognized as the most useful and widely applicable type of objective test elements. They could be used to measure the most important educational outcomes, such as understanding, knowledge, judgment, and problem-solving.

By preparing these MCQs once after completing every topic, we are able to attempt the competitive exams like NEET easily and effectively.

Let us look at the work power energy MCQs. Let us go through the MCQ on work power and energy with answers.


1. The Bullet That Has Fired from a Gun Can Pierce a Target Due to Its __________?

  1. Heat energy

  2. Mechanical energy

  3. Acceleration

  4. Kinetic energy

Answer: (d)

Explanation

The kinetic energy of a body by the virtue of its motion is known as kinetic energy. Any moving object can do work. Thus, a bullet that is fired from a gun can pierce a target due to its kinetic energy.


2. A Person Holds a Bucket by Applying a 10n Force. He Then Moves a Horizontal Distance of 5m and Climbs up a Vertical Distance of 10m. Find Out the Total Work Done by Him?

  1. 100J

  2. 150J

  3. 50J

  4. 200J

Answer: (a)

Explanation

s = 5m, F = 10N, and θ = 90°

Work done is given by, W1=F scos θ = 10 × 5 × cos 90° = 0

In the case of vertical motion, the angle between force and displacement is 0°

Here, F = 10N, s = 10m, and θ=0°

So, work done, W2 = 10 × 10 × cos0 = 100J

Therefore, the total work done = W1 + W2 = 100J.


3. A Gardener Pushes a Lawn Roller Via a Distance of 20m. If He Applies a Force of 20kg Weight in a Direction Inclined at 60° to the Ground, Then What Will Be the Work Done by Him? (g=9.8m/s2)

  1. 400J

  2. 1960J

  3. 250J

  4. 2514J

Answer: (b)

Explanation

F = 20kg wt = 20 × 9.8N, s = 20m, and θ = 60°

W = Fscosθ = 20 × 9.8 × 20 × cos⁡60°

So, W = 1960J.


4. When a Working Coolie Walks on a Horizontal Platform Having a Load on His Head, the Work Done by Him on the Load is Zero. Identify the Statement True or False?

  1. False

  2. True

Answer: (b)

Explanation

When a working coolie walks on a horizontal platform with a load on his head, he applies force in the upward direction, which is equal to its weight. The load-displacement is along the horizontal direction. Thus the work done by him on the load is zero.


5. The Work Done by the Centripetal Force for a Body Moving in a Circular Path is __________?

  1. Negative

  2. Zero

  3. Constant

  4. Positive

Answer: (b)

Explanation

For a body that moves in a circular path, the displacement and the centripetal force are perpendicular to each other. Thus, the work done or accomplished by the centripetal force is zero.


6. When a Cylinder Filled With Gas is Fitted With a Movable Piston is Allowed to Expand, Then the Work Done by the Gas is Positive. Identify the Statement True or False?

  1. True

  2. False

Answer: (a)

Explanation

When a gas that is filled in a cylinder fitted with a movable piston is allowed to expand, the work done by the gas results positively, because of the force due to the displacement and gas pressure act in the same direction.


7. Consider an Object With Mass M Such That it is Accelerated Uniformly from Rest and the Speed Attained by the Object, V in Time, T. Calculate the Instantaneous Power Delivered to the Body in Terms of the Function of Time

  1.  ½ \[\frac{m\nu ^{2}}{T^{2}}\] t

  2. ½ \[\frac{m\nu ^{2}}{T^{2}}\] t2

  3. \[\frac{m\nu ^{2}}{T^{2}}\] t

  4. \[\frac{m\nu ^{2}}{T^{2}}\] t2

Answer: (c)


8. What is the Average Power Required to Lift a Mass of 100kg to a Height of 50m in 50 Seconds?

  1. 100

  2. 980

  3. 50

  4. 5000

Answer: (b)

FAQ (Frequently Asked Questions)

1. What is the Engine Power When the Velocity of the Car is ‘v’, Mass as ‘m,’ Acceleration as ‘a,’ and External Resistance ‘r’?

  1. (R-ma)v

  2. (R+ma)v

  3. Mav

  4. Rv

Answer: (2)

2. A Ball, Thrown from a Height of 20 M Downward Vertically and Has an Initial Velocity of V20. as the Stone Collided With the Ground, it Lost 50% of Its Energy and Bounced Back to the Same Height. Identify the Initial Velocity Here?

  1. 28m/s

  2. 20m/s

  3. 10m/s

  4. 14m/s

Answer: (2)

3. What Will Be the Average Power That is Required to Lift a Mass of 100kg to a Height of 50m in 50 Seconds of Time?

  1. 980

  2. 100

  3. 50

  4. 5000

Answer: (1)

4. Calculate the Energy That is Lost in a Perfectly Inelastic Collision If the Mass of the Object is Given as 40kg With a Velocity of 4m/s Hits the Object of a Mass Having 60kg With Velocity 2m/s

  1. 440J

  2. 110J

  3. 392J

  4. 48J

Answer: (4)

5. By How Much Percentage Does the Kinetic Energy Increase If the Momentum is Increased by 20%?

  1. 55%

  2. 66%

  3. 44%

  4. 77%

Answer: (3)

6. Identify the Ratio of Velocities of a Nucleus That Splits Into Two Parts With a Radii of 1:2?

  1. 4:1

  2. 6:1

  3. 2:1

  4. 8:1

Answer: (4)