Q. No.
In an orbital motion, the angular momentum vector is
1. Along the radius vector
2. Parallel to the linear momentum
3. In the orbital plane
4. Perpendicular to the orbital plane
An automobile engine develops 100 kW when rotating at a speed of 1800 rev/min. What torque does it deliver ?
1. 350 N-m
2. 440 N-m
3. 531 N-m
4. 628 N-m
A circular disc A of radius r is made from an iron plate of thickness t and another circular disc B of radius 2r and thickness . The relation between moments of inertia and is
1.
2.
3.
4. Depends on the actual values of t and r
A sphere is rolling down a plane of inclination to the horizontal. The acceleration of its centre down the plane is
1. g sin
2. less than g sin
3. greater than g sin
4. zero
A particle of mass \(m\) moves with a constant velocity along \(3\) different paths, \(DE, OA\) and \(BC\). Which of the following statements is not correct about its angular momentum about point \(O\)?
| 1. | It is zero when it is at \(A\) and moving along \(OA\). |
| 2. | The same at all points along the line \(DE\). |
| 3. | Of the same magnitude but oppositely directed at \(B\) and \(D\). |
| 4. | Increases as it moves along the line \(BC\). |
A bob of mass m attached to an inextensible string of length l is suspended from vertical support. The bob rotates in a horizontal circle with an angular speed about the vertical. About the point of suspension.
| 1. | Angular momentum is conserved |
| 2. | Angular momentum changes in magnitude but not in the direction |
| 3. | Angular momentum changes in direction but not in magnitude |
| 4. | Angular momentum changes both in direction and magnitude |
A particle of mass 2 kg located at the position m has a velocity of 2 m/s. Its angular momentum about z-axis in kg- is :
1. +4
2. +8
3. -4
4. -8
A cylinder of mass 'M' is suspended by two strings wrapped around it as shown. The acceleration 'a' and the tension T when the cylinder falls and the string unwinds itself are, respectively,
1.
2.
3.
4.
Given below are two statements:
Assertion (A):
The speed of whirlwind in a tornado is alarmingly high.
Reason (R):
If no external torque acts on a body, its angular velocity remains conserved.
1.
Both (A) and (R) are true and (R) is the correct explanation of (A).
2.
Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.
(A) is true but (R) is false.
4.
Both (A) and (R) are false.
© 2025 GoodEd Technologies Pvt. Ltd.