CBSE Class 11 Physics Oscillations MCQs Set C

Question. Lissajous figure obtained by combining x = a sin ϖt and y = a sin (ϖt + π/4) will be a/an
(a) ellipse
(b) straight line
(c) circle
(d) parabola
Answer: a

Question. The displacement of a particle is represented by the equation y = 3cos (π/4 – 2ϖ) The motion of the particle is
(a) simple harmonic with period 2p/w
(b) simple harmonic with period p/w
(c) periodic but not simple harmonic
(d) non-periodic
Answer: b

Question. Motion of an oscillating liquid column in a U-tube is
(a) periodic but not simple harmonic
(b) non-periodic
(c) simple harmonic and time period is independent of the density of the liquid
(d) simple harmonic and time period is directly proportional to the density of the liquid
Answer: c

Question. A particle of mass 10 gm is describing S.H.M. along a straight line with period of 2 sec and amplitude of 10 cm. Its kinetic energy when it is at 5 cm from its equilibrium position is
(a) 37.5π² erg
(b) 3.75π² erg
(c) 375π² erg
(d) 0.375π² erg
Answer: c

Question. The period of oscillation of a mass M suspended from a spring of negligible mass is T. If along with it another mass M is also suspended, the period of oscillation will now be
(a) T
(b) T / √2
(c) 2T
(c) √2 T
Answer: d

Question. If the magnitude of displacement is numerically equal to that of acceleration, then the time period is
(a) 1 second
(b) π second
(c) 2π second
(d) 4π second
Answer: c

Question. A particle of mass 1 kg is moving in S.H.M. with an amplitude 0.02 and a frequency of 60 Hz. The maximum force acting on the particle is
(a) 144 π²
(b) 188 π²
(c) 288 π²
(d) None of these
Answer: c

Question. The equation of SHM of a particle is A + 4π²x = 0 where a is instantaneous linear acceleration at displacement x. The frequency of motion is
(a) 1 Hz
(b) 4p Hz
(c) 1/4 Hz
(d) 4 Hz
Answer: a

Question. When an oscillator completes 100 oscillations its amplitude reduces to 1/3 of its initial value. What will be its amplitude, when it completes 200 oscillations ?
(a) 1/8
(b) 2/3
(c) 1/6
(d) 1/9
Answer: d

Question. A circular hoop of radius R is hung over a knife edge. The period of oscillation is equal to that of a simple pendulum of length
(a) R
(b) 2R
(c) 3R
(d) 3R/2
Answer: b

Question. A tunnel has been dug through the centre of the earth and a ball is released in it. It executes S.H.M. with time period
(a) 42 minutes
(b) 1 day
(c) 1 hour
(d) 84.6 minutes
Answer: d

Question. The equation of motion of a particle is x = a cos(at)₂. The motion is
(a) periodic but not oscillatory
(b) periodic and oscillatory
(c) oscillatory but not periodic
(d) neither periodic nor oscillatory
Answer: c

Question. When two displacements represented by y₁ = asin(ϖt) and y₂ = b cos(ϖt) are superimposed the motion is:
(a) simple harmonic with amplitude a/b
(b) simple harmonic with amplitude √a² + b²
(c) simple harmonic with amplitude (a + b) /2
(d) not a simple harmonic
Answer: b

Question. 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)
Answer: b

Question. A clock which keeps correct time at 20ºC, is subjected to 40ºC. If coefficient of linear expansion of the pendulum is 12 × 10^–6 per ºC. How much will it gain or loose in time ?
(a) 10.3 seconds/day
(b) 20.6 seconds/day
(c) 5 seconds/day
(d) 20 minutes/day
Answer: a

Question. The displacement of a particle varies with time according to the relation y = a sinϖt + b cosϖt.
(a) The motion is oscillatory but not SHM
(b) The motion is SHM with amplitude a + b
(c) The motion is SHM with amplitude a² + b²
(d) The motion is SHM with amplitude √a² + b²
Answer: d

Question. A particle executes S.H.M. having time period T, then the time period with which the potential energy changes is
(a) T
(b) 2 T
(c) T/2
(d) ∝
Answer: c

Question. A rectangular block of mass m and area of cross-section A floats in a liquid of density r . If it is given a small vertical displacement from equilibrium. It undergoes oscillations with a time period T then
(a) T∝ m
(b) T∝ p
(c) T∝1/A
(d) T∝1/ p
Answer: a

Question. Acceleration of a particle executing SHM, at it’s mean position is
(a) infinity
(b) variable
(c) maximum
(d) zero
Answer: d

Question. Which one of the following equations of motion represents simple harmonic motion?
(a) Acceleration = – k(x + a)
(b) Acceleration = k(x + a)
(c) Acceleration = kx
(d) Acceleration = – k₀x + k₁x²
where k, k₀, k₁ and a are all postive.
Answer: a

Question. A particle is acted simultaneously by mutually perpendicular simple harmonic motion x = a cos wt and y = a sin wt. The trajectory of motion of the particle will be
(a) an ellipse
(b) a parabola
(c) a circle
(d) a straight line
Answer: c

Question. A particle executing SHM maximum speed of 30 cm/s and a maximum acceleration of 60 cm/s². The period of oscillation is
(a) π sec
(b) (π/2) sec
(c) 2p sec
(d) (π/t) sec
Answer: a

Question. Two simple pendulums of length 0.5 m and 20 m respectively are given small linear displacement in one direction at the same time. They will again be in the phase when the pendulum of shorter length has completed oscillations [nT₁=(n–1)T₂, where T₁ is time period of shorter length & T₂ be time period of longer wavelength and n are no. of oscillations completed]
(a) 5
(b) 1
(c) 2
(d) 3
Answer: b

Question. A child swinging on swing 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.
Answer: b

Question. The graph plotted between the velocity and displacement from mean position of a particle executing SHM is
(a) circle
(b) ellipse
(c) parabola
(d) straight line
Answer: b

Question. A vertical mass-spring system executes simple harmonic oscillations with a period of 2s. A quantity of this system which exhibits simple harmonic variation with a period of 1 s is
(a) velocity
(b) potential energy
(c) phase difference between acceleration and displacement
(d) difference between kinetic energy and potential energy
Answer: b