## Class 11 Physics Objective Chapter – 14 Oscillations

Here we are providing NCERT Class 11 Physics Objective Chapter – 14 Oscillations Chapter Wise MCQs for board exam is very important for board exam preparation. This book explains all the concepts and topics in very simple language that the students can easily understand the complex subjects also. This NCERT Class 11 Physics MCQs Chapter – 14 Oscillations Chapter consist all important topic regarding NCERT Class 11 Physics Objective Chapter – 14 Oscillations. This book basically covers all the major and minor elements that together form a democratic government. Topics like power-sharing, federalism, democracy and diversity, political parties, consequences of democracy, challenges to democracy etc. have been discussed in the NCERT Class 11 Physics Objective Chapter – 14 Oscillations. The question papers in CBSE board exams are generally based on the latest NCERT books. Hence, students must follow the NCERT book to prepare effectively for their Class 11 Physics exam. If you want color notes then click here

## Class 11 Physics Objective Chapter – 14 Oscillations

1. In damped oscilation the directions of the restoring force and the resistive force

( a )  are the same

( b )  are opposite

( c )  may be same or opposite

( d )  have no relation with each other

Ans:-( c )

2. In S.H.M, the vibration of which of the following is not a sine curve?

( a )  Timeperiod

( b )  Velocity

( c )  Displacement

( d )  Acceleration

Ans:-( a )

3. In S.H.M., the particle is

( a ) always accelerated

( b ) always retarded.

( c ) neither accelerated nor retarded.

( d ) accelerated and retarded alternately.

Ans:-( d )

4. A particle executes simple harmonic motion between x = – A and x = + A. The time taken for it to go from O to A/2 is T1 and Tand to go from A/2 to A is T2. Then

( a )  T1 < T2

( b )  T1 > T2

( c )  T1 = T2

( d )  T1 = 2T2

Ans:-( a )

5. The equation of SHM is y = a Sin (  2 pnt + α  ) , then its phase at time ‘t’ is

( a )  α

( b )  2pnt

( c )  2pnt + α

( d )  2πt

Ans:-( c )

6. The function sin ω t – cos ωt represents

( a )  a simple harmonic motion with a period π/ω.

( b )  a simple harmonic motion with a period 2π/ω.

( c )  a periodic, but not simple harmonic motion with a period π/ω.

( d )  a periodic, but not simple harmonic motion with a period 2π/ω.

Ans:-( b )

7. Which of the following is not essential for S.H.M.?

( a ) Gravity

( b ) Restoring force

( c ) Inertia

( d ) Material medium

Ans:-( a )

8. The displacement y of a particle executing periodic motion is given by y = 4 cos² ( t/2 )  sin ( 1000t ) . This expression may be considered to be a result of superposition of the following number of harmonic motions

( a )  two

( b )  three

( c )  four

( d )  five

Ans:-( b )

9. Damping in oscillatory motion is caused by

( a )  Friction

( b )  Restoring force

( c )  Both restoring force and friction

( d )  Neither friction nor restoring force

Ans:-( a )

10.Grap of potential energy vs. displacement of a S.H. Oscillator is

( a ) parabolic

( b ) hyperbolic

( c ) elliptical

( d ) linear

Ans:-( a )

11. For an oscillating simple pendulum, the tension in the string is

( a )  maximum at extreme position

( b )  maximum at mean position

( c )  constant throughout the motion

( d )  cannot be predict

Ans:-( b )

12. In SHM, the acceleration is directly proportional to

( a )  time

( b )  linear velocity

( c )  displacement

( d )  frequency

Ans:-( c )

13. A block of mass 200 g executing SHM under the influence of a spring of spring constant k = 90 N m–1 and a damping constant b = 40 g s–1. The time elapsed for its amplitude to drop to half of its initial value is ( Given ln ( 1/2 )  = –0.693 )

( a )  7 s

( b )  9 s

( c )  4 s

( d )  11 s

Ans:-( a )

14. The bob of a simple pendulum is a spherical hollow ball filled with water. A plugged hall near the bottom of the oscillating bob gets suddenly unplugged. During observation, till water is coming out, the time -period of the oscillation would

( a ) first decrease and then increase to the original value

( b ) first increase and then decrease to the original value

( c ) increase towards a saturation value

( d ) remain unchanged

Ans:-( b )

15. Spring is pulled down by 2 cm. What is amplitude of motion?

( a )  0 cm

( b )  6 cm

( c )  2 cm

( d )  cm

Ans:-( c )

16. What determines the frequency of natural oscillations of the system?

( a )  Elasticity alone

( b )  Inertia alone

( c )  Both elasticity and inertia

( d )  Neither elasticity nor inertia

Ans:-( c )

17. In the case of forced oscillations, which of the following statements is not true?

( a ) frequency equals that of external periodic force

( b ) amplitude depends upon the damping coefficient

( c ) amplitude tends to infinity at resonance

( d ) higher the damping coefficient, lower is the amplitude at resonance

Ans:-( c )

18. A simple pendulum is set into vibrations. The bob of the pendulum comes to rest after some time due to

( a )  Air friction

( b )  Moment of inertia

( c )  Weight of the bob

( d )  Combination of all the above

Ans:-( a )

19. The displacement of a particle in simple harmonic motion in one time period is [A = amplitude]

( a )  A

( b )  2 A

( c )  4 A

( d )  Zero

Ans:-( d )

20. A particle executes SHM of type x = Asinwt. It takes time t1 from x = 0 to x = A/2 and t2 from x = A/2 to x = A. The ratio t1 : t2 will be

( a )  1 : 1

( b )  1 : 2

( c )  1 : 3

( d )  2 : 1

Ans:-( b )

21. The restoring force acting on the particle executing S.H.M. is

( a ) directly proportional to displacement.

( b ) inversely proportional to displacement.

( c ) directed in the same direction as the displacement.

( d ) independent of displacement.

Ans:-( a )

22. One of the two clocks on the earth is controlled by a pendulum and other by a spring. If both the clocks are taken to the moon, then which clock will have the same time – period of the earth?

( a )  spring clock

( b )  pendulum clock

( c )  both

( d )  none

Ans:-( a )

23. Which of the following quantities connected with S.H.M. do not vary periodically?

( a )  Displacement

( b )  Velocity

( c )  Acceleration

( d )  Total energy

Ans:-( d )

24. In SHM, the acceleration is directly proportional to

( a ) displacement

( b ) time

( c ) linear velocity

( d ) frequency

Ans:-( a )

25. The ratio of energies of oscillations of two exactly identical pendulums oscillating with amplitudes 5 cm and 10 cm is : ( a )  1 : 2 ( b )  2 : 1 ( c )  1 : 4 ( d )  4 : 1 61. A child swinging on wing in sitting position stands up. The time period of the swing will

( a )  increase

( b )  decrease

( c )  remain same

( d )  increase if the child is tall and decrease if the child is short.

Ans:-( c )

26. For a body executing simple harmonic motion, which parameter comes out to be non-periodic ?

( a )  Displacement

( b )  Velocity

( c )  Acceleration

( d )  None of these

Ans:-( d )

27. Which of the following relationships between the acceleration a and the displacement x of a  particle involve simple harmonic motion?

( a )  a = 0.7 x

( b )  a = –200 x2

( c )  a = –10 x

( d )  a = 100 x3

Ans:-( c )

28. A particle executing SHM has a maximum speed of 30 cm/s and a maximum acceleration of 60 cm/s2. The period of oscillation is

( a ) πs

( b ) π/2 s

( c ) 2 πs

( d ) π/t s

Ans:-( a )

29. When a particle performing uniform circular motion of radius 10 cm undergoes the SHM, what will be its amplitude?

( a )  10 cm

( b )  5 cm

( c )  2.5 cm

( d )  20 cm

Ans:-( a )

30. Which of the following characteristics does not change due to the damping of S.H.M.?

( a )  Amplitude

( b )  Time period

( c )  Angular frequency

( d )  Initial phase

Ans:-( d )

31. The acceleration of particle executing S.H.M. when it is at mean position is

( a ) Infinite

( b ) Varies

( c ) Maximum

( d ) Zero

Ans:-( d )

32. A spring-mass system oscillates with a frequency n. If it istaken in an elevator slowly accelerating upward, the frequency will

( a )  increase

( b )  decrease

( c )  remain same

( d )  become zero

Ans:-( c )

33. A system exhibiting SHM must possess

( a )  inertia only

( b )  elasticity as well as inertia

( c )  elasticity, inertia and an external force

( d )  elasticity only

Ans:-( b )

34. A spring balance has a scale that reads from 0 to 50 kg. The length of the scale is 20 cm. A block of mass m is suspended from this balance when displaced and released, it oscillates with a period 0.5 s. The value of m is ( Take g = 10 m s–2 )

( a )  8 kg

( b )  12 kg

( c )  16 kg

( d )  20 kg

Ans:-( c )

35. The equation of motion of a particle is x = a cos ( αt ) 2. The motion is

( a ) periodic but not oscillatory

( b ) periodic and oscillatory

( c ) oscillatory but not periodic

( d ) neither periodic nor oscillatory

Ans:-( c )

36. For a magnet of time period T magnetic moment is M, if the magnetic moment becomes one fourth of the initial value, then the time period of oscillation becomes

( a )  Half of initial value

( b )  One fourth of initial value

( c )  Double of initial value

( d )  Four time initial value

Ans:-( c )

37. Which of the following is not the characteristic of S.H.M.?

( a )  Periodic nature

( b )  Displacement time graph is a sine curve.

( c )  Acceleration is zero at mean position.

( d )  Projection of a uniform circular motion on any straight line.

Ans:-( d )

38. For a magnet of time period T magnetic moment is M, if the magnetic moment becomes one fourth of the initial value, then the time period of oscillation becomes

( a ) Half of initial value

( b ) One fourth of initial value

( c ) Double of initial value

( d ) Four time initial value

Ans:-( c )

39. Select the correct statement( s )  from the following

I. Motion of a satellite and a planet is periodic as well as SHM.

II. Mass suspended by a spring executes SHM.

III. Motion of a simple pendulum is always SHM.

( a )  I only

( b )  II only

( c )  I and II

( d )  I, II and III

Ans:-( b )

40. A particle moves in a circular path with a uniform speed. Its motion is

( a )  periodic

( b )  oscillatory

( c )  simple harmonic

( d )  angular simple harmonic

Ans:-( a )

41. A particle executes simple harmonic motion between x = – A and x = + A. The time taken for it to go from 0 to A/2 is T1 and to go from A/2 to A is T2. Then

( a )  T1 < T2

( b )  T1 > T2

( c )  T1 = T2

( c )  T1 = 2T2

Ans:-( a )

42. If a simple harmonic oscillator has got a displacement of 0.02 m and acceleration equal to 2.0 ms-2 at any time, the angular frequency of the oscillator is equal to

Ans:-( a )

43. Time period of simple pendulum of length l and a place where acceleration due to gravity is g is T. what is the period of a simple pendulum of the same length at a place where the acceleration due to gravity is 1.029 is,

( a )  T

( b )  1.02 T

( c )  0.99 T

( d )  1.01 T

Ans:-( c )

44. The amplitudes of two similar pendulums are 2 cm and 5 cm. The ratio of their energies is

( a )  2 : 5

( b )  5 : 2

( c )  4 : 25

( d )  None of the above

Ans:-( c )

45. A system exhibiting SHM must possess

( a ) elasticity as well as inertia

( b ) elasticity, inertia and an external force

( c ) elasticity only

( d ) inertia only

Ans:-( a )

46. A simple spring has length l and force constant K. It is cut into two springs of lengths l1 and l2 such that l1 = n l2 ( n = an integer ) . The force constant of spring of length l1 is

( a )  K ( 1 + n )

( b )  ( K/n )  ( 1 + n )

( c )  K

( d )  K/( n + 1 )

Ans:-( b )

47. The displacement of a particle is given by r = A (  i coswt + jsinwt  )  r  . The motion of the particle is

( a )  simple harmonic

( b )  on a straight line

( c )  on a circle

( d )  with constant acceleration.

Ans:-( c )

48. When the displacement of a particle executing SHM is one-fourth of its amplitude, what fraction of the total energy is the kinetic energy?

( a )  16/15

( b )  15/16

( c )  3/4

( d )  4/3

Ans:-( b )

49. The period of a simple harmonic oscillator is 2 sec. The ratio of its maximum velocity and maximum acceleration is

( a ) Π

( b ) 1/Π

( c ) 2Π

( d ) 4

Ans:-( b )

50. In the case of forced oscillations, which of the following statements is not true

( a )  frequency equals that of external periodic force

( b )  amplitude depends upon the damping coefficient

( c )  amplitude tends to infinity at resonance

( d )  higher the damping coefficient, lower is the amplitude at resonance

Ans:-( c )

51. The amplitude of a simple harmonic oscillator is doubled, then

( a )  its energy is doubled.

( b )  maximum velocity is doubled.

( c )  time period is doubled.

( d )  time period remains same.

Ans:-( d )