Back to SYSTEM OF PARTICLES

Your Progress

0 / 58 Answered

Correct

Incorrect

Accuracy

NEET • PHYSICS • SYSTEM OF PARTICLES

System of particles practice · Easy

Choose an answer to check it, or open “View answer” to study the explanation. Sign in to save progress to your account.

Practice format and chapter quiz

The practice player uses single-correct-answer MCQs. Chapter quizzes help you review a topic; they are not full-length NEET mock papers.

Take a chapter quiz →

Showing 31-58 of 58 questions

Preparing practice and saved progress…

31 Easy

31 of 58

Application +4 | -1

Three particle of masses 8 kg, 4 kg, 4kg are at (4,1) (-2,2) and (1,-3) respectively. If they are acted upon by forces

16j, -6i

and

14i

newton’s respectively, acceleration of the centre of mass of the system is

View answer and explanation

Correct option: D

None

None of the options are correct. The acceleration of the center of mass is calculated by dividing the net force acting on the system by the total mass. The correct acceleration is (2/4)i + (16/4)j = i/2 + 4j m/s², which is not among the given options.

32 Easy

32 of 58

Application +4 | -1

The angular speed of fly wheel moving with uniform angular acceleration changes from 1200 rpm to 3120 rpm in 16 seconds. The angular acceleration in

\mathrm{rad/}{\mathrm{s}^2}

is:

View answer and explanation

Correct option: C

4\,\pi

Option C (

4\pi

) is correct because the angular acceleration is calculated using the change in angular speed over time, converting rpm to rad/s.

33 Easy

33 of 58

Application +4 | -1

A ring of radius 1 m and mass 20 kg is rotating about is diameter with angular velocity of 40 rad/sec. Its kinetic energy is

View answer and explanation

Correct option: C

8000 J

Option C (8000 J) is correct because the kinetic energy of a rotating ring is given by

KE = \frac{1}{2}I\omega^2

, where I is the moment of inertia about the diameter and

\omega

is the angular velocity.

34 Easy

34 of 58

Application +4 | -1

The speed of a motor decreases from 1200 rpm to 600 rpm in 20s. The total number of rotations it makes before coming to rest.

View answer and explanation

Correct option: A

400

Option A (400) is correct because it is calculated by finding the angular deceleration, time to stop, and then using the angular displacement formula.

35 Easy

35 of 58

Application +4 | -1

An automobile engine develops 50 kW when rotating at a speed of 900 rev/min. The torque it delivers (in N-m)

View answer and explanation

Correct option: B

530.7

Option B (530.7) is the closest to the correct answer because the torque is calculated using the formula

P = \tau \omega

, where P is power and

\omega

is angular speed in rad/s.

36 Easy

36 of 58

Remembering +4 | -1

1^{\circ}

is equal to

View answer and explanation

Correct option: D

Both (1) and (2)

Option D (Both (1) and (2)) is correct because 1 degree is equal to

\frac{\pi}{180}

radians and also equal to 60 arcminutes.

37 Easy

37 of 58

Application +4 | -1

If all of a sudden the radius of the earth decreases, then

View answer and explanation

Correct option: B

The angular speed of the earth will increase

Option B (The angular speed of the earth will increase) is correct because if the radius decreases, the moment of inertia decreases, and to conserve angular momentum, the angular speed must increase.

38 Easy

38 of 58

Application +4 | -1

The angular displacement of a particle is 5 rad. Then its angular velocity at

t = 10\,sec

\left( {rad{s^{ - 1}}} \right)

View answer and explanation

Correct option: B

0.5

Option B (0.5) is correct because angular velocity is defined as the angular displacement divided by the time taken, given a constant angular velocity.

39 Easy

39 of 58

Application +4 | -1

A uniform solid sphere of diameter 0.2 m and mass 10 kg is rotated about its diameter with an angular velocity of

2\,rad\,{s^{ - 1}}

. Then its angular momentum in

kg\,{m^2}\,{s^{ - 1}}

View answer and explanation

Correct option: C

0.08

Option C (0.08) is correct because it is the angular momentum calculated using the formula L = Iω, where I is the moment of inertia of a solid sphere and ω is the angular velocity.

40 Easy

40 of 58

Application +4 | -1

A constant torque of 500 N-m turns a wheel of moment of inertia

100\,kg - {m^2}

about axis through its centre. Its angular velocity after 6 sec is

View answer and explanation

Correct option: C

30\,\frac{{rad}}{{\sec }}

Option C (

30\,\frac{{rad}}{{\sec }}

) is correct because it is the angular velocity calculated using the formula relating torque, moment of inertia, and angular acceleration.

41 Easy

41 of 58

Application +4 | -1

A thick straight wire of length

4\pi \,m\,

is fixed at its midpoint and the bent in the form of a circle. The shift in its centre of mass is

View answer and explanation

Correct option: C

2 m

Option C (2 m) is correct because when the wire is bent into a circle, the center of mass shifts from the midpoint of the wire to the center of the circle, which is a distance equal to the radius of the circle.

42 Easy

42 of 58

Application +4 | -1

Two objects of mass 100 g and 400 g posses velocity

5\hat i\,m/s

and

3\hat i + 3\hat j\,m/s

respectively. The velocity of their centre of mass in m/s is

View answer and explanation

Correct option: C

\frac{{17\hat i + 12\hat j}}{5}

Option C (

\frac{{17\hat i + 12\hat j}}{5}

) is correct because the velocity of the center of mass is calculated by

v_{cm} = \frac{{m_1v_1 + m_2v_2}}{{m_1 + m_2}}

43 Easy

43 of 58

Understanding +4 | -1

The total linear momentum of a system of particle about the centre of mass is

View answer and explanation

Correct option: C

Zero

Option C (Zero) is correct because the total linear momentum of a system of particles about the center of mass is always zero.

44 Easy

44 of 58

Application +4 | -1

A sphere of mass 10kg and radius 1m rotates about a tangent. The moment of inertia of the solid sphere is

View answer and explanation

Correct option: A

14\,kg - {m^2}

Option A (

14\,kg - {m^2}

) is correct because the moment of inertia about a tangent is

I = I_{CM} + Md^2 = \frac{2}{5}MR^2 + MR^2

, where

d = R

45 Easy

45 of 58

Application +4 | -1

A point mass

(m)

is located at

(0, a)

. Where should the

2 m

mass be kept, so that centre of mass lies at origin?

View answer and explanation

Correct option: A

\left(0, \frac{-a}{2}\right)

Option A

\left(0, \frac{-a}{2}\right)

is correct because it places the 2m mass such that the weighted average position is at the origin.

Explore Other Chapters in PHYSICS

View All →

UNITS & MEASUREMENTS 392 MCQs WORK-ENERGY-POWER 355 MCQs MECHANICAL PROPERTIES OF FLUIDS 317 MCQs MOTION IN PLANE 307 MCQs MAGNETIC EFFECT OF CURRENT 282 MCQs THERMAL PROPERTIES OF MATTER 269 MCQs

46 Easy

46 of 58

Application +4 | -1

A boat of mass 20 kg is at rest. A dog of mass 1 kg in the boat with a velocity of

5\,m{s^{ - 1}}

. What is the velocity of boat (nearly)?

View answer and explanation

Correct option: D

0.24\,m{s^{ - 1}}

Option D is correct. Using conservation of momentum, the velocity of the boat is calculated to be approximately 0.24 m/s in the opposite direction of the dog.

47 Easy

47 of 58

Remembering +4 | -1

Centre of mass for a uniform semi-circular ring will be at (from centre)

View answer and explanation

Correct option: A

\frac{{2R}}{\pi }

Option A (

\frac{{2R}}{\pi }

) is correct because the center of mass of a uniform semi-circular ring is located at a distance of

\frac{{2R}}{\pi }

from the center.

48 Easy

48 of 58

Application +4 | -1

A wheel of mass 16 kg has a moment of inertia of 160 kg-m² about its own axis, the radius of gyration will be

View answer and explanation

Correct option: D

3.2 m

Option D (3.2 m) is correct because the radius of gyration is calculated using the formula

k = \sqrt{\frac{I}{M}}

, where I is the moment of inertia and M is the mass.

49 Easy

49 of 58

Analyzing +4 | -1

For the same total mass, which of the following will have the largest moment of inertia about an axis passing through the centre of mass and perpendicular to the plane of the body

View answer and explanation

Correct option: D

Four rods forming a square of side

2 R

Option D (Four rods forming a square of side

2 R

) is correct because it has the mass furthest from the axis of rotation.

50 Easy

50 of 58

Application +4 | -1

Consider a system of two identical particles in which first one is accelerating with

2 {~m} / {s}^2

and second one is at rest. The centre of mass of this system will have an acceleration

View answer and explanation

Correct option: B

1 {~m} / {s}^2

Option B (

1 {~m} / {s}^2

) is correct because the acceleration of the center of mass is the average of the individual accelerations, weighted by mass.

51 Easy

51 of 58

Application +4 | -1

A body is rotating with angular velocity

\omega = \left( {3\hat i - 4\hat j - \hat k} \right)

. The linear velocity of a point having position vector

r = \left( {5\hat i - 6\hat j + 6\hat k} \right)

View answer and explanation

Correct option: C

- 30\hat i - 23\hat j + 2\hat k

Option C (

- 30\hat i - 23\hat j + 2\hat k

) is correct because the linear velocity is calculated using the cross product of angular velocity and position vector:

v = \omega \times r

52 Easy

52 of 58

Analyzing +4 | -1

Statement I: Total torque on a system is independent of
the origin if the total external force is zero.
Statement II: Torque due to a couple is independent of
the origin.

View answer and explanation

Correct option: A

Statement I is true, Statement II is true; Statement II is
the correct explanation for Statement I

Option A (Statement I is true, Statement II is true; Statement II is the correct explanation for Statement I) is correct because both statements are true and Statement II explains Statement I.

53 Easy

53 of 58

Understanding +4 | -1

A uniform circular disc has a radius of 20 cm. A circular disc of radius 10 cm is cut concentrically from the original disc. The shift in the centre of mass is

View answer and explanation

Correct option: D

Zero

Option D is correct. Since the circular disc is cut concentrically, the center of mass remains at the same location, which is the center of the disc. Therefore, the shift in the center of mass is zero.

54 Easy

54 of 58

Application +4 | -1

A cylinder of mass M, length L and radius R. If its moment of inertia about an axis passing through its centre and perpendicular to its axis is minimum, the ratio L/R must be equal to

View answer and explanation

Correct option: D

\sqrt {3/2}

Option D (

\sqrt {3/2}

) is correct because minimizing the moment of inertia leads to the given ratio.

55 Easy

55 of 58

Application +4 | -1

If a sphere of mass 4 kg and diameter 10 cm is rolling at speed

10\,m{s^{ - 1}}

. Its rotational kinetic energy is

View answer and explanation

Correct option: C

80 J

Option C (80 J) is correct because the rotational kinetic energy is calculated using the formula

KE = \frac{1}{2}I\omega^2

, where I is the moment of inertia of the sphere and

\omega

is the angular velocity.

56 Easy

56 of 58

Understanding +4 | -1

A uniform wire of length 6.28 cm is bent in the form of a circle. The shift in its centre of mass is

View answer and explanation

Correct option: A

1 cm

Option A (1 cm) is correct because when the wire is bent into a circle, the center of mass shifts from the midpoint of the wire to the center of the circle, which is a distance equal to the radius of the circle minus half the original length.

57 Easy

57 of 58

Understanding +4 | -1

Given below are two statements : one is labelled as
Assertion (A) and the other is labelled as Reason
(R).

Assertion (A) : The angular speed of the moon in
its orbit about the earth is more than the angular
speed of the earth in its orbit about the sun.

Reason (R) : The moon takes less time to move
around the earth than the time taken by the earth to
move around the sun.

In the light of the above statements, choose the
most appropriate answer from the options given
below:

View answer and explanation

Correct option: D

Both (A) and (R) are correct and (R) is the
correct explanation of (A)

Option D (Both (A) and (R) are correct and (R) is the correct explanation of (A)) is correct because the moon's shorter orbital period around the Earth directly results in a higher angular speed compared to the Earth's orbit around the Sun.

58 Easy

58 of 58

Application +4 | -1

Two bodies of masses 3 kg and 2 kg moves with an acceleration are

2\,m{s^{ - 2}}

and

4\,m{s^{ - 2}}.

Find the acceleration of centre of mass in

m{s^{ - 2}}

View answer and explanation

Correct option: C

2.8

Option C (2.8) is correct because the acceleration of the center of mass is calculated using the formula

a_{CM} = \frac{m_1a_1 + m_2a_2}{m_1 + m_2}

Revision notes and key takeaways

Review SYSTEM OF PARTICLES in your textbook or class notes, then use this set to check your understanding.

Showing 31-58 of 58 questions

Your Progress

System of particles practice · Easy

Explore Other Chapters in PHYSICS

Continue Your Practice

Your practice