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Q1. A body of mass 5 kg revolves in a circle of diameter 0.60m, making 1000 revolution per minute. Then, the linear velocity of body is:

• 40 π m/s
• 20 π m/s
• 30 π m/s
• 10 π m/s

Solution

Q2. A rifle shoots a bullet horizontally at a speed v=200 m/s. At the same time, a bullet is dropped from the same height as the bullet that left the rifle. Ignoring all effects due to air resistance, which bullet reaches the ground first?

• The bullet that was shot
• The bullet that was dropped
• They reach at the same time
• Need to know the mass of the bullet

Solution

Both the bullets have the same initial height. Hence they take the same amount of time to reach the ground. It is also clear from the equations y = (1/2) g t²

Q3. If an object is dropped through the window of a fast running train. Then

• the object will follow an elliptical path
• the object moves straight horizontally.
• the object falls down vertically.
• to a man standing near the track, path of the object will be a part of parabola.

Solution

To a man standing near the track, path of the object will be parabolic.

Q4. Two vectors are equal if and only if

• they have the same magnitude
• they have the same magnitude and direction
• they have same direction
• they coincide with each other

Solution

Vectors are characterized by the magnitude as well as direction.

Q5. The dot product of mutually perpendicular vectors is always:

• Vector
• Non-Zero Scalar
• Null vector
• Zero

Solution

Q6. If the magnitude of two vectors is 4 and 5 and the value of their scalar product is 10, then the angle between vectors is:

• 60^o
• 45^o
• 30^o
• 90^o

Solution

Q7. If a projectile is thrown with a velocity 10 ms^-1 at an angle of 30⁰ with the horizontal. Then the time of flight will be

• 2 s
• 1 s
• 3 s
• 4 s

Solution

Q8. A body is thrown with a velocity of 10 m/s at an angle of 60 degrees with the horizontal. Its velocity at the highest point is:

• zero
• 10 m/s
• 8.67 m/s
• 5 m/s

Solution

At the highest point, the horizontal velocity is u cos 60^o = 10x1/2 = 5 m/s

Q9. The distance travelled by an object along the axes are given by x = 2t² ,y = t²-4t, z = 3t - 5 . The initial velocity of the particle is

• 3 units  
• 12 units  
• 5 units
• 2 units  

Solution

Q10. A body of mass 15 kg revolves in a circle of diameter 1.20m, making 100 revolution per minute. Then, the linear velocity of body is:

• 40 π m/s
• 20 π m/s
• 30 π m/s
• 10 π m/s

Solution

Q11. The vector product of parallel vectors is always:

• Vector
• Scalar
• Null vector
• One

Solution

Q12. The quantity which remains unchanged during the flight of an oblique projectile is

• Vertical component of acceleration
• Horizontal component of acceleration
• Vertical component of velocity
• Horizontal component of velocity

Solution

The quantity which remains unchanged during the flight of an oblique projectile is horizontal component of velocity

Q13. Magnitude of resultant of two vectors, A and B is given by square root of:

• A² - B² + 2AB cosθ
• A² + B² - 2AB cosθ
• A² - B² - 2AB cosθ
• A² + B² + 2AB cosθ

Solution

Magnitude of resultant of two vectors, A and B is given by square root of A² + B² + 2AB cosθ

Q14. A cart moves with a constant speed along a horizontal circular path. From the cart, a particle is thrown up vertically with respect to the cart, the particle will,

• follow a straight line path  
• follow a circular path  
• follow a parabolic path
• follow an elliptical path  

Solution

The path will follow a parabolic path.

Q15. Which one of the following is not an example of projectile?

• A bullet fired from a gun.
• A kicked football.
• A javelin thrown by an athlete.
• Taking off of an aircraft.

Solution

Taking off of an aircraft is not an example of a projectile motion.

Q16. A force of 20 N acts on a body and displaces it 2m along the direction of force. Then the work done by the force is:

• 40 J
• 20 J
• 10 J
• 15 J

Solution

W = F.S cos θ^o = 20 × 2 cos 0^o = 40 J

Q17. Find the odd one out:

• area
•  velocity
• force
• current

Solution

Current is the scalar quantity, whereas area, velocity, force are vector quantities.

Q18. The angular speed of a flywheel making 210 revolutions per minute is:

• 44 radian/s
• 22 radian/s
• 20 radian/s
• 15 radian/s

Solution

Q19. At the top point of a projectile, angle between the directions of its velocity and acceleration is

• 0^o
• 45⁰
• 90^o
• 180^o

Solution

Q20. At what angle should a projectile with initial velocity 'v' be thrown, so that it achieves its maximum range?

• 45°
• 30°
• 60°
• 90°

Solution

For maximum horizontal rangeH_max= (u²sin2)/2g = (u²)/2g, implying the angle  should be equal to 45°._.

Q21. Which statement is true for a ball thrown at 20 degrees with the horizontal, when it is at the highest point in its trajectory?

• Its velocity and acceleration are both zero
• Its velocity is perpendicular to its acceleration
• Its velocity is zero but its acceleration is nonzero
• Its velocity is nonzero but its acceleration is zero

Solution

The acceleration is always g pointing down at all times during flight. So (a) and (d) are not correct. The y-component of velocity is zero, but it is still moving in the x-direction, so (c) is not correct. At the top the motion is in the x direction only and the acceleration is in the y direction, so the two are perpendicular.

Q22. At maximum height during the journey of a projectile, which quantity becomes zero?

• vertical component of acceleration
• horizontal component of acceleration
• vertical component of velocity
• horizontal component of velocity

Solution

The vertical component of velocity becomes zero at maximum height.

Q23. Which of the following is the vector quantity?

• Pressure
• Temperature
• Electric current
• Weight of the body

Solution

Weight = mg Where, gravitational constant-g is a vector quantity. The product of vector and scalar is also a vector. Thus, the weight is a vector quantity.

Q24. A tennis ball bounces higher on hills than on planes. Which statement gives the correct reason-

• value of g on hills is more than that of plane
• value of g on hills is less than that of plane
• value of temperature is lower on hills
• atmospheric pressure is lower on hills

Solution

     and g is less on hills.

Q25. The angular speed of a wheel of radius 0.50 m moving with the speed of 20 m/s is:

• 40 radian/s
• 20 radian/s
• 10 radian/s
• 30 radian/s

Solution

Q26. If velocity of P with respect to Q is 40 km/h, then velocity of Q with respect to P is

• 40 km/h
• 0 km/h
• -40 km/h
• insufficient information given

Solution

as velocity of A wrt B is negative of velocity of B wrt A.

Q27. A vector A points towards east and vector B points north then A x B points

• vertically downward
• vertically upward
• south
• north-east

Solution

The vector product can be found using right hand rule. Point your fingers in the east direction and curl them towards the north, your thumb will point in the direction of A x B

Q28. Two forces, whose magnitude are at the ratio of 3:5 give a resultant of 35 N. If angle of inclination is 60^o, then the magnitude of each force is:

• 25 N, 5N
• 15N, 25N
• 10N, 25N
• 5 N , 3N

Solution

Let the two forces be: 3x and 5x Resultant = 35 N Angle of inclination: 60^o Now, according to parallelogram law of vector addition, we have: R= 35 N = After solving above equation, we get: x = 5 and two forces are: 15N and 25N respectively.

Q29. The angular speed of a wheel of radius 0.50 m moving with the speed of 20 m/s is:

• 40 radian/s
• 20 radian/s
• 10 radian/s
• 30 radian/s

Solution

 

Q30. A monkey is running on the ground, next to a train, in the direction of the train. The speed of the monkey is 5km/h and the speed of the train is 100km/h. What is the velocity of the monkey with respect to the train?

• 105km/h in the direction of the train
• 95 km/h in the direction opposite to the train.
• 95 km/h in the direction of the train
• 105km/h in the direction opposite to the train

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