A body in SHM crosses the mean position every:
A T
B T/2
C T/4
D 2T
It crosses mean position twice during one time period.
The potential energy in SHM is maximum at:
A Mean position
B Extreme positions
C At any random position
D At zero displacement
Maximum displacement → maximum P.E.
If the frequency of SHM is doubled, time period becomes:
A Half
B Double
C Same
D Four times
T=1/fT = 1/fT=1/f.
SHM is the projection of:
A Uniform linear motion
B Uniform circular motion
C Projectile motion
D Non-uniform circular motion
Shadow of uniform circular motion gives SHM.
When velocity is maximum in SHM, acceleration is:
A Zero
B Minimum
C Maximum
D Constant
At mean position → v max, a = 0.
The restoring force constant k has unit:
A N·m
B N/m
C J
D kg/m
Spring constant unit = N/m.
Phase difference between velocity and displacement in SHM is:
A 0°
B 90°
C 180°
D 270°
Velocity leads displacement by 90°.
If amplitude is 5 cm, maximum acceleration is ω2A\omega^2 Aω2A. For A = 0.05 m:
A depends only on ω
B cannot be found
C is independent of ω
D zero
aₘₐₓ = ω²A.
In SHM, if amplitude becomes zero, the motion becomes:
A Non-linear
B Uniform motion
C Oscillatory
D No motion
No displacement → no oscillation.
Which of the following is not characteristic of SHM?
A Periodic motion
B Restoring force
C Acceleration ∝ − displacement
D Speed always constant
SHM speed is not constant.
In lightly damped oscillations, time period:
A Decreases
B Increases slightly
C Becomes zero
D Infinite
Damping reduces frequency slightly → T increases.
Work done by damping force is:
A Positive
B Negative
C Zero
D Infinite
Damping removes energy → negative work.
Forced oscillations achieve steady state when:
A Natural frequency matches driving frequency
B Transients die out
C Damping becomes zero
D Energy becomes zero
Steady state occurs after transient oscillations vanish.
Resonance amplitude becomes very large when:
A Damping is very high
B Damping is zero
C Driving frequency = natural frequency
D Both B and C
No damping + resonance → very high amplitude.
In an RLC electrical circuit, resonance occurs when:
A Xₗ = Xc
B R = 0
C L = C
D XC = 0
Inductive and capacitive reactances equal → resonance.
Coupled oscillations give rise to:
A Beats
B Resonance only
C Standing waves
D Longitudinal waves
Energy transfer between oscillators → alternations in amplitude → beats.
At resonance in forced oscillations, the power absorbed is:
A Minimum
B Maximum
C Zero
D Constant
Maximum energy transfer at resonance.
Which system has highest Q-factor?
A Pendulum in air
B Car shock absorber
C Tuning fork
D Door closer
Tuning fork oscillates with very low damping.
In damping, energy decays:
A Linearly
B Logarithmically
C Exponentially
D Randomly
Amplitude ∝ e^(−bt/2m).
Critical damping is used in:
A Clocks
B Measuring instruments
C Musical instruments
D Loudspeakers
Needed for quick response with no oscillation.
A wave whose particles vibrate perpendicular to direction of wave is:
A Longitudinal
B Transverse
C Surface wave
D Torsional wave
Transverse motion.
Wave speed depends on:
A Source of sound
B Nature of medium
C Amplitude
D Phase
Medium properties determine speed.
For a wave travelling in +x direction, general equation is:
A y = A sin(ωt + kx)
B y = A sin(ωt − kx)
C y = A sin(kx)
D y = A cos(ωt)
Negative sign → wave travelling positive x.
When two waves superpose, displacement at a point equals:
A Geometric sum
B Vector sum
C Algebraic sum
D Zero
Principle of superposition.
If two waves differ in phase by π/2, they are:
A In phase
B Out of phase completely
C Partially out of
Velocity of wave along a string depends on:
A Length
B Tension & linear density
C Frequency
D Amplitude
v=T/μv = \sqrt{T/\mu}v=T/μ.
When a wave passes through a boundary, which parameter remains constant?
A Speed
B Wavelength
C Frequency
D Amplitude
Frequency depends on the source, not medium.
For destructive interference, phase difference must be:
A 0
B π
C 2π
D 4π
Opposite phase → destructive interference.
In a transverse wave, trough corresponds to:
A Minimum displacement
B Maximum displacement
C Zero displacement
D Maximum velocity
Trough is lowest point of wave.
Energy transported by a wave is proportional to:
A A
B A²
C A³
D A⁴
Energy ∝ amplitude².
A standing wave does NOT transfer:
A Momentum
B Energy
C Displacement
D Mass
Net energy transfer is zero.
In an open pipe, distance between consecutive nodes is:
A λ/2
B λ/4
C λ
D 3λ/4
Same as on strings.
Which frequency is NOT present in a closed organ pipe?
A 1st harmonic
B 3rd harmonic
C 5th harmonic
D 2nd harmonic
Even harmonics absent.
In fundamental mode of open pipe, number of antinodes is:
A 1
B 2
C 3
D 0
Open at both ends → antinode at each end.
Wavelength of n-th harmonic in string of length L:
A 2L/n
B L/2n
C 4L/n
D nL
λₙ = 2L/n.
For a standing wave, pressure nodes correspond to:
A Displacement nodes
B Displacement antinodes
C Zero density
D Maximum density
Pressure node ↔ displacement antinode in sound.
If frequency doubles in a string, number of loops:
A Halves
B Doubles
C Same
D Zero
Loops ∝ frequency.
If string tension increased 4 times, frequency becomes:
A Half
B Double
C Four times
D Same
f∝Tf ∝ \sqrt{T}f∝T.
Beats occur when two waves have:
A Same frequency
B Slight difference in frequency
C Different speeds
D Different amplitudes
Δf small → beats.
Beat frequency = |f₁ − f₂|. If beat = 5 Hz, f₁ = 250 Hz. Possible f₂ is:
A 245 Hz
B 255 Hz
C Both A & B
D None
Difference must be 5.
Sound waves are:
A Transverse
B Longitudinal
C Electromagnetic
D Polarised
Compression–rarefaction mechanism.
Speed of sound is maximum in:
A Air
B Water
C Steel
D Vacuum
Stronger restoring forces in solids.
In a medium, speed of sound increases with:
A Density
B Elasticity
C Pressure
D Frequency
v = √(elasticity/density).
Unit of sound intensity:
A Watt
B Watt/m²
C Joule
D Decibel
Intensity = power/area.
If distance from source doubles, intensity becomes:
A Half
B One-fourth
C Double
D Four times
I ∝ 1/r².
Ultrasound frequency is:
A < 20 Hz
B 20–20,000 Hz
C > 20,000 Hz
D 100 Hz
Above audible range.
Bats use:
A Infrared radiation
B Sonar
C Echolocation
D UV waves
Bats emit ultrasound for navigation.
In Doppler effect, there is change in:
A Speed of wave
B Wavelength and frequency
C Only amplitude
D Only wavelength
Relative motion changes both λ and f.
Shock waves are produced when:
A Object speed < sound
B Object speed = sound
C Object speed > sound
D No motion
Supersonic motion → shock waves.
Reverberation time increases when:
A Absorbing materials are added
B Reflecting surfaces increase
C Room size decreases
D Windows opened
Reflective surfaces prolong persistence of sound.