A bucket full of water is revolved in vertical circle of radius 2m. What should be the maximum time-period of revolution so that the water doesn't fall off the bucket ?

1. 1 sec

2. 2 sec

3. 3 sec

4. 4 sec

Subtopic:  Uniform Circular Motion |
 52%
Level 3: 35%-60%
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A tube of length L is filled completely with an incompressible liquid of mass M and closed at both the ends. The tube is then rotated in a horizontal plane about one of its ends with a uniform angular velocity ω. The force exerted by the liquid at the other end is 

1. MLω22

2. MLω2

3. MLω24

4. ML2ω22

Subtopic:  Application of Laws |
 61%
Level 2: 60%+
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A car is moving in a circular horizontal track of radius \(10~\text{m}\) with a constant speed of \(10~\text{m/s}\). A plumb bob is suspended from the roof of the car by a light rigid rod of length \(1.00~\text{m}\). The angle formed by the rod with respect to the vertical is:

1. zero 2. \(30^{\circ}\)
3. \(45^{\circ}\) 4. \(60^{\circ}\)
Subtopic:  Banking of Roads |
 78%
Level 2: 60%+
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A long horizontal rod has a bead that can slide along its length and is initially placed at a distance \(L\) from one end \(A\) of the rod. The rod is set in angular motion about \(A\) with constant angular acceleration \(𝛼\). If the coefficient of friction between the rod and the bead is \(μ\), and gravity is neglected,  assuming the rod provides the transverse normal reaction, then the time after which the bead starts slipping is:

1. \(\sqrt{\dfrac{\mu}{\alpha}}\)
2. \(\dfrac{\mu}{\sqrt{\alpha}}\)
3. \(\dfrac{1}{\sqrt{\mu\alpha}}\)
4. Infinitesimal

Subtopic:  Uniform Circular Motion |
 57%
Level 3: 35%-60%
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A particle is moving with a constant speed along a straight-line path. A force is not required to:

1. increase its speed.
2. decrease its momentum.
3. change its direction.
4. keep it moving with uniform velocity.

Subtopic:  Newton's Laws |
 81%
Level 1: 80%+
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A mass of \(1\ \text{kg}\) is suspended by a string \(A\). Another string \(C\) is connected to its lower end as shown in the given figure. If a sudden jerk is given to \(C\), then:

  

1. The portion \(AB\) of the string will break
2. The portion \(BC\) of the string will break
3. None of the strings will break
4. The mass will start rotating

Subtopic:  Application of Laws |
 60%
Level 2: 60%+
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In the given figure, a mass \(m\) is suspended by string \(A\). Another string \(C\) is connected to its lower end. If the string \(C\) is stretched slowly, then:

                                       

1. The portion \(AB\) of the string will break
2. The portion \(BC\) of the string will break
3. None of the strings will break
4. None of the above

Subtopic:  Application of Laws |
 65%
Level 2: 60%+
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Newton's second law gives the measure of:

1. Acceleration
2. Force
3. Momentum
4. Angular momentum

Subtopic:  Newton's Laws |
 56%
Level 3: 35%-60%
PMT - 1982
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A coin is dropped in a lift. It takes time \(t_1\) to reach the floor when the lift is stationary. It takes time \(t_2\) when the lift is moving up with constant acceleration. Then:
1. \(t_1 > t_2\)
2. \(t_1 < t_2\)
3. \(t_1 = t_2\)
4. \(t_1 >> t_2\)

Subtopic:  Application of Laws |
 65%
Level 2: 60%+
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If the tension in the cable of \(1000~\text{kg}\) elevator is \(1000~\text{kg}\) weight, the elevator:

1. is accelerating upwards.

2. is accelerating downwards.

3. may be at rest or accelerating.

4. may be at rest or in uniform motion.

Subtopic:  Newton's Laws |
 75%
Level 2: 60%+
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