# Physics GK 05 - Work, Energy and Power

1. Which of the following is NOT correct about an inelastic collision?
[A] Linear momentum is conserved
[B] Kinetic energy is conserved
[C] Total energy is conserved
[D] Some or all the forces involved may be non-conservative in nature

2. The dot product of two vectors A and B is equal to the product of magnitude of A and B and __________?
[A] cosine of the largest angle between them
[B] sine of the largest angle between them
[C] cosine of the smallest angle between them
[D] sine of the smallest angle between them

3. What is the dot product of two perpendicular vectors?
[A] 1
[B] 0
[C] -1
[D] 1/2

4. Work done is defined as the dot product of which of the following vectors?
[A] Force and acceleration
[B] Force and area
[C] Force and instantaneous velocity
[D] Force and displacement

5. What is the dimensional formula of work done?
[A] M1 L1 T-1
[B] M1 L2 T-1
[C] M1 L-1 T-2
[D] M1 L2 T-2

6. Which of the following is NOT correct about units of work:
[A] 1 joule = 107 ergs
[B] 1 kg-m = 1 joule
[C] 1 kg-m = 9.8 joule
[D] 1 joule = 1 Nm

7. Work done will NOT be zero in which of the following case/cases?
[A] When displacement is zero
[B] When angle between force and displacement vector is zero
[C] When angle between force and displacement vector is 90°
[D] When force is zero

8. The work done by a variable force is given by:
[A] area under the force curve and the displacement axis
[B] square of the area under the force curve and the displacement axis
[C] natural log of the area under the force curve and the displacement axis
[D] twice the area under the force curve and the displacement axis

9. Which of the following is NOT a conservative force?
[A] Electrostatic force
[B] Magnetic force
[C] Force in an elastic spring
[D] Frictional force