NTA will shortly release the JEE Main Syllabus 2025 at jeemain.nta.ac.in. Last Year, the complete syllabus of JEE Main underwent some major changes. According to the latest syllabus guidelines, the weightage of Physics has dropped to 22.5%. Due to these changes in the syllabus, certain shifts in chapter-wise weightage have been observed. Rotational Motion are among such topics. It’s among the least weightage topics in JEE Main Physics Syllabus 2025. This chapter holds 1.39% weightage in the whole syllabus.

  • Rotational Motion is a part of the General Physics section, and every year around 2-3 questions are asked from this chapter. Due to the drop in weightage, you can expect 1-2 questions in JEE Main 2025.
  • Rotational Motion in JEE Mains Physics Syllabus 2025 covers all the basic concepts on units and measurements, fundamentals of units, dimensions etc.

Aspirants consider Rotational Motion as one of the Easiest Chapters in Physics for JEE Main 2025. Even though this chapter has the least weightage in the syllabus, to develop a strong foundation in physics, this particular chapter plays a pivotal role. Hence the candidates need to develop a clear understanding of this chapter. The list of most asked questions from this chapter will help the students with their preparation.

Must Check News on JEE Main Physics:

Some of the most important topics in rotational motion for the JEE Main exam include:

  • Moment of inertia: A topic that is considered relatively easier than other rotational motion concepts, as it involves understanding and applying formulas to calculate moments of inertia for various shapes.
  • Angular velocity and acceleration: These are important topics to focus on for the JEE Main practice paper.
  • Torque and rotational equilibrium: A topic to revise for the JEE Main exam.
  • Angular momentum: A topic to revise for the JEE Main exam.
  • Kinematics of rotational motion: A topic to revise for the JEE Main exam.
  • Rolling motion: A topic to revise for the JEE Main exam.
  • Rotational kinetic energy: A topic to revise for the JEE Main exam.

Here are some tips for tackling rotational motion problems in the JEE Main exam:

  • Understand key concepts like angular displacement, velocity, and acceleration.
  • Apply the analogous equations of motion to rotating bodies.
  • Utilize conservation of angular momentum and energy principles.
  • Practice diverse problem sets to hone your skills.

Rotational Motion JEE Mains Questions -

List Of Most Asked Questions With Solutions

In the (JEE) Main, the topic of Physics and Measurement often features questions that have appeared multiple times in previous years. Many questions in this section are either repeated or follow similar patterns, with only minor changes, such as different numerical values or slight modifications in wording.Certain questions have been repeated as many as five times.

Here are some of the most frequently asked and repeated questions:

Question 1:

A person of 80 kg mass is standing on the rim of a circular platform of mass 200 kg, rotating about its axis at 5 revolutions per minute (rpm). The person now starts moving towards the center of the platform. What will be the rotational speed (in rpm) of the platform when the person reaches its center? ______. (This question has been asked thrice- JEE Main 2017,JEE Main 2021,JEE Main 2020 )

Question 2:

A wheel is rotating freely with an angular speed ω on a shaft. The moment of inertia of the wheel is I, and the moment of inertia of the shaft is negligible. Another wheel of moment of inertia 3I, initially at rest, is suddenly coupled to the same shaft. The resultant fractional loss in the kinetic energy of the system is: (This question has been asked thrice- JEE Main 2017,JEE Main 2021,JEE Main 2020 )

Options:

A. 5/6

B. 1/4​

C. 0

D. 3/4

Question 3:

For a uniform rectangular sheet shown in the figure, the ratio of moments of inertia about the axes perpendicular to the sheet and passing through O (the center of mass) and O' (corner point) is: (This question has been asked twice-JEE Main 2022,JEE Main 2024 )

Options:

A. 2/3

B. 1/4

C. 1/8

D. 1/2

Question 4:

A long cylindrical vessel is half-filled with a liquid. When the vessel is rotated about its own vertical axis, the liquid rises up near the wall. If the radius of the vessel is 5 cm and its rotational speed is 2 rotations per second, then the difference in heights between the center and the sides, in cm, will be: (This question has been asked twice-JEE Main 2019,JEE Main 2024 )

Options:

A. 2.0

B. 0.1

C. 0.4

D. 1.2

Question 6:

To mop-clean a floor, a cleaning machine presses a circular mop of radius R vertically down with a total force F and rotates it with a constant angular speed about its axis. If the force F is distributed uniformly over the mop and the coefficient of friction between the mop and the floor is µ, the torque applied by the machine on the mop is: (This question has been asked twice-JEE Main 2022,JEE Main 2019 )

Question 7:

Let the moment of inertia of a hollow cylinder of length 30 cm (inner radius 10 cm and outer radius 20 cm) about its axis be 1. The radius of a thin cylinder of the same mass such that its moment of inertia about its axis is also I, is: (This question has been asked twice-JEE Main 2022,JEE Main 2019 )

Options:

A. 12 cm

B. 16 cm

C. 14 cm

D. 18 cm

Question 8:

The following bodies are made to roll up (without slipping) the same inclined plane from a horizontal plane:

(i) a ring of radius R

(ii) a solid cylinder of radius R/2

(iii) a solid sphere of radius R/4

If, in each case, the speed of the center of mass at the bottom of the incline is the same, the ratio of the maximum heights they climb is: (This question has been asked twice-JEE Main 2022,9 April 2019 I )

Options:

A. 4: 3: 2

B. 10: 15: 7

C. 20: 15: 14

D. 2: 3: 4

Question 9:

A force of 40 N acts on a point B at the end of an L-shaped object, as shown in the figure. The angle θ that will produce the maximum moment of the force about point A is given by:

(This question has been asked thrice-JEE Main 2021,JEE Main 2018,JEE Main 2017 )

Question 10:

In a physical balance working on the principle of moments, when a 5 mg weight is placed on the left pan, the beam becomes horizontal. Both the empty pans of the balance are of equal mass. Which of the following statements is correct? (This question has been asked thrice-JEE Main 2021,JEE Main 2020,JEE Main 2017 )

Options:

A. Left arm is longer than the right arm

B. Both the arms are of the same length

C. Left arm is shorter than the right arm

D. Every object that is weighed using this balance appears lighter than its actual weight.

Sol:1

Answer: 9rpm

Sol:2

Answer: 3/4

Sol:3

Answer: 1/4

Sol:4

Answer: 2cm

Sol:6

Sol:7

Answer:16 cm

Sol:8

Sol:9

Answer: 1/2

Sol:10