MCQs on Work Power and Energy – Chapter-6

MCQs on Work Power and Energy

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1 – The change in the kinetic energy of an object is

1. Is not equal to the work done on it by the net force.
2. Is inversely promotional to the work done on it by the net force.
3. Is equal to the work done on it by the net force.
4. Is twice the work done on it by the net force?

Answer 3

2- Pick the right formula:

W = work done by the force

F = Force in the direction of displacement

d = magnitude of displacement

1. W = F*d
2. W = F /d
3. W = F*F/d
4. W = F / d*d

 

Answer 1

3 – What is the formula of kinetic energy?

K = Kinetic Energy

m = mass

v = velocity

1. K = mv*v
2. K = 2*m*v*v
3. K = (1/2)*m*v*v
4. K = (1/3)*m*v*v

Answer 3

4 – What is the work done by the external party against gravitational force:

m = mass, h = height, and g = acceleration on an object due to the gravity 

1. mg/h
2. mgh
3. m / g
4. g /m

Answer 2

5 – The work done by the external agency against gravitational force is stored as

1. Potential energy
2. Kinetic Energy
3. Gravitational Energy
4. Centrifugal energy

Answer 1

6 – Work completed by a conservative force depends on

1. Start position only
2. Final position only
3. Either starting or final position
4. Start and Final position only

Answer 4

7 – If a ball of mass m is released from the stationary position from the top of an inclined plane that has no friction, what is the speed at the bottom:

1. 2gh
2. 2g/h
3. gh
4. √2gh

Answer 4

• The units of potential energy

1. Is the same as that of Kinetic Energy and Work
2. Is the same as that of Kinetic Energy but not the same as that of  Work
3. Is the same as that of work but not the same as that of kinetic energy
4. Is not the same as that of kinetic energy and work

Answer 1

8 – The exothermic reaction ………. energy and endothermic reaction………… energy

• Absorbs, Releases
• Releases, Absorbs
• Releases, Releases
• Absorbs, Absorbs

9 – What is the equivalence of mass and energy equation?

E = energy, m = mass and c = speed of light

1. E = m*c*c
2. E = m*c
3. E = m*c/c
4. E = m/c

Answer 1

K Work is zero when

1. Movement is zero
2. There is no force
3. Force and movement is at 90 degrees
4. All of the above

Answer 4

L The work performed on an object moving in a circle is

1. Zero
2. Infinity
3. Negative
4. Positive

Answer 1

M Someone is sliding a piece of furniture weighing 100 Kg out of a loaded truck on a ramp at an angle of 45 degrees. Work by normal force is 

1. 45,00
2. 100
3. 450
4. Zero

Answer 4

O. A car starts to break and stops in 50 m. The force exerted by road on the car is 300 N and is in opposite direction to the movement of the car. Work done by road on the car is 

1. 15,000 J
2. – 15,000 J
3. 5,000 J
4. -5,000 J

Answer 2

P. Friction is ______ force

1. Conservative
2. Non Conservative
3. Sometimes conservative sometimes non-conservative
4. Neither Conservative nor Non-Conservative

Answer 2

Q Spring force is ____ force 

1. Conservative
2. Non Conservative
3. Sometimes conservative sometimes non-conservative
4. Neither Conservative nor Non-Conservative

Answer 1

R. Mechanical energy of a system is the ____ of kinetic energy and potential energy

1. Multiplication
2. Sum
3. Subtraction
4. square

Answer 2

S. A body moves from point A to B. The sum of mechanical and potential energy at point A and at point B is constant. The mechanical energy of the system is hence a 

1. Nonconservative force
2. Conservative force
3. Neither conservative nor nonconservative
4. Insufficient information available to answer this question

Answer 2

T. Gravity is__________ force 

1. Conservative
2. Non Conservative
3. Sometimes conservative sometimes nonconservative
4. Neither Conservative nor Non-Conservative

Answer 1

U. A metal square hits a spring mounted on a floor horizontally, consider the mass of square 100 Kg and speed 10 m/s when it hit spring. What is the compression of the spring 

Spring constant 3.25 1000 N/m

1. 2 m
2. 1.35 m
3. 1.75 m
4. 2.75 m

Answer 3