JEE Main and Advanced Physics MCQs - Work, Energy and Rotational Motion (Set 3)

Q1. A force of 10 N pulls a block 5 m along the floor. The force makes an angle of 60° with the direction of motion. How much work does the force do?

a) 50 J

b) 0 J

c) 25 J

d) 43.3 J

Q2. The speed of a 2 kg body increases from 2 m/s to 4 m/s. What is the net work done on it?

a) 4 J

b) 16 J

c) 8 J

d) 12 J

Q3. A pump lifts 600 kg of water to a height of 10 m in 1 minute. What is its minimum power output? (g = 10 m/s²)

a) 600 W

b) 6,000 W

c) 1,000 W

d) 100 W

Q4. A spring of spring constant 200 N/m is compressed by 10 cm. How much elastic potential energy does it store?

a) 1 J

b) 20 J

c) 10 J

d) 2 J

Q5. If the linear momentum of a body is doubled, its kinetic energy becomes:

a) Half

b) Double

c) Four times

d) Unchanged

Q6. A 2 kg ball moving at 6 m/s hits a 1 kg ball at rest and they stick together. How much kinetic energy is lost?

a) 12 J

b) 0 J

c) 24 J

d) 36 J

Q7. A stone tied to a string moves in a vertical circle of radius 2 m. What is the minimum speed at the lowest point for it to just complete the circle? (g = 10 m/s²)

a) 20 m/s

b) 10 m/s

c) 5 m/s

d) √20 m/s

Q8. A 2 kg mass is at x = 0 and a 3 kg mass is at x = 5 m. Where is their centre of mass?

a) x = 2.5 m

b) x = 3.5 m

c) x = 2 m

d) x = 3 m

Q9. What is the moment of inertia of a thin uniform ring of mass M and radius R about any diameter?

a) ¼MR²

b) 2MR²

c) ½MR²

d) MR²

Q10. A uniform rod of mass 3 kg and length 2 m rotates about an axis through one end, perpendicular to the rod. What is its moment of inertia?

a) 12 kg m²

b) 1 kg m²

c) 4 kg m²

d) 2 kg m²

Q11. A 10 N force acts tangentially on the rim of a uniform disc of mass 2 kg and radius 0.5 m, free to rotate about its central axis. What is its angular acceleration?

a) 20 rad/s²

b) 40 rad/s²

c) 10 rad/s²

d) 5 rad/s²

Q12. A spinning skater pulls in her arms so that her moment of inertia becomes half. What happens to her rotational kinetic energy?

a) It halves

b) It becomes four times

c) It doubles

d) It stays the same

Q13. A solid sphere rolls without slipping. What fraction of its total kinetic energy is rotational?

a) 2/5

b) 2/7

c) 5/7

d) 1/2

Q14. A solid sphere starts from rest and rolls without slipping down an incline of vertical height 7 m. What is its speed at the bottom? (g = 10 m/s²)

a) 10 m/s

b) √98 m/s

c) √140 m/s

d) 14 m/s

Q15. A ring, a disc and a solid sphere of equal mass and radius are released together from the top of the same rough incline and roll without slipping. Which reaches the bottom first?

a) Ring

b) Solid sphere

c) Disc

d) All reach together