Given below are two statements: 
Assertion (A): When a cyclist doubles his speed of turning, the chance of his skidding becomes nearly four times.
Reason (R): When the speed of the vehicle increases, the angle of bending also increases.
  
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.
Subtopic:  Banking of Roads |
Level 3: 35%-60%
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When a heavy mass and lighter mass of a certain material is placed on a surface, then compared to lighter mass, the coefficient of friction between the heavy mass and the surface will: 
 
1. increase 
2. decrease
3. remain unchanged
4. become zero
Subtopic:  Friction |
 70%
Level 2: 60%+
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A rocket with a lift-off mass of \(20,000\) \(\mathrm{kg}\) is blasted upwards with an initial acceleration of \(5~\mathrm{ms}^{-2}\). Then initial thrust (force) of the blast is:
(Take \(g=10\) \(\mathrm{ms}^{-2}\))
1. \(7 \times 10^5 \mathrm{~N} \)
2. \(0 \)
3. \(2 \times 10^5 \mathrm{~N} \)
4. \(3 \times 10^5 \mathrm{~N}\)

Subtopic:  Application of Laws |
 69%
Level 2: 60%+
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A stone of mass \(m\) tied to the end of a string revolves in a vertical circle of radius \(R.\) The magnitude of net forces at the lowest and highest points of the circle directed vertically downwards are:
(\(T_1\) and denote the tension and speed at the lowest point. \(T_2\) and \(v_2\) denote corresponding values at the highest point.)
Lowest point Highest point
1. \(mg-T_1 \) \(mg+T_2 \)
2. \(mg+T_1\) \(mg+T_2\)
3. \(mg+T_1-\frac{mv^2_1}{R}\)
\(mg-T_2+\frac{mv^2_2}{R}\)
4. \(mg-T_1-\frac{mv^2_1}{R}\) \(mg+T_2+\frac{mv^2_2}{R}\)

Subtopic:  Non Uniform Vertical Circular Motion |
 54%
Level 3: 35%-60%
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A car of mass \(1000\) kg negotiates a banked curve of radius \(90\) m on a frictionless road. If the banking angle is of \(45^\circ,\) the speed of the car is:

1. \(20\) ms–1 2. \(30\) ms–1
3. \(5\) ms–1 4. \(10\) ms–1
Subtopic:  Banking of Roads |
 90%
Level 1: 80%+
AIPMT - 2012
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A block \(B\) is pushed momentarily along a horizontal surface with an initial velocity \(v.\) If \(\mu\) is the coefficient of sliding friction between \(B\) and the surface, the block \(B\) will come to rest after a time: 
 
1. \(v \over g \mu\)
2. \(g \mu \over v\)
3. \(g \over v\)
4. \(v \over g\)

Subtopic:  Friction |
 81%
Level 1: 80%+
AIPMT - 2007
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A particle moving with velocity \(\vec{v}\) is acted by three forces shown by the vector triangle \({PQR}.\) The velocity of the particle will:

         

1. change according to the smallest force \({\overrightarrow{Q R}}\)
2. increase
3. decrease
4. remain constant
Subtopic:  Newton's Laws |
 80%
Level 1: 80%+
NEET - 2019
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A point mass \(m\) is moved in a vertical circle of radius \(r\) with the help of a string. The velocity of the mass is \(\sqrt{7gr} \) at the lowest point. The tension in the string at the lowest point is:

1. \(6 \text{mg}\) 2. \(7 \text{mg}\)
3. \(8 \text{mg}\) 4. \( \text{mg}\)
Subtopic:  Non Uniform Vertical Circular Motion |
 64%
Level 2: 60%+
NEET - 2020
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Given below are two statements:
Assertion (A): It is observed that when a car brakes suddenly, the passengers are thrown forward.
Reason (R): (Newton's 1st Law of Motion) Everybody continues in its state of rest or of uniform motion in a straight line except in so far as it be compelled by an externally impressed force to act otherwise.
 
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. (A) is False but (R) is True.
Subtopic:  Newton's Laws |
 70%
Level 2: 60%+
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A block of mass \(m\) slides down a smooth plane inclined at an angle of \(60^\circ\) with the horizontal. The normal reaction of the incline acting on the block equals:
1. \(mg\sin60^\circ\) 2. \(mg\cos60^\circ\)
3. \(mg\tan60^\circ\) 4. \(mg\cot60^\circ\)
Subtopic:  Tension & Normal Reaction |
 83%
Level 1: 80%+
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