Physics

Wave Motion

489 Questions

Wave motion questions cover the principles of traveling and stationary waves, including their equations and intensities. The topics explore interference patterns, phase differences, and electromagnetic radiation speeds. Mastery of these concepts is vital for physics sections in engineering and civil services examinations.

Wave interferenceStanding wavesPhase differenceElectromagnetic radiationWave equations

Wave Motion Questions

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

Transverse mechanical wave can travel in

  1. Iron rod

  2. Hydrogen gas

  3. Water surface

  4. Stretched string
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation

Transverse waves can travel only in solids and only along the surface of liquids, but not in the entire liquid. They can't travel in gases.

Since iron rod and stretched string are solids, transverse waves can travel in them.
Water surface being a liquid surface they can travel in it also.
Hydrogen gas being a gas, they can't travel in it.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

Which of the following does not identify a necessary property of wave motion?

  1. transmission of energy

  2. periodic motion

  3. disturbance

  4. a material medium
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In any wave motion, energy is always transferred to the next particle which is succeeding the previous particle.  In a wave motion, particles are oscillating in a direction perpendicular to the direction of propagation or parallel. Since oscillation is a periodic motion,  we can say that periodic motion is always associated with the wave.  An oscillatory disturbance is always imparted the next and next particle and this is how the disturbance Travels across the particles.  Ordinary waves require a material medium for propagation. But electromagnetic waves do not require any material medium. They can also propagate through vacuum. Thus material medium is not a necessary condition for all wave motions.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

During propagation of a plane progressive mechanical wave :

  1. all the particles are vibrating in the same phase

  2. amplitude of all the particles is equal

  3. particles of the medium execute S.H.M.

  4. wave velocity depends upon the nature of the medium
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

During propagation of a plane progressive mechanical wave amplitude of all the particles is equal, particle of the medium execute S.H.M, wave velocity depends upon the nature of the medium and all the particles are vibrating in the different phase.

Hence $B, C$ and $D$ are correct options.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

Waves that are combination of longitudinal and transverse nature are

  1. water waves

  2. light waves

  3. shock waves

  4. sound waves
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water waves are an example of waves that involve a combination of both longitudinal and transverse motions. As a wave travels through the waver, the particles travel in clockwise circles. The radius of the circles decreases as the depth into the water increases. The animation at right shows a water wave travelling from left to right in a region where the depth of the water is greater than the wavelength of the waves. I have identified two particles in orange to show that each particle indeed travels in a clockwise circle as the wave passes.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

A transverse wave travels along z-axis. The particles of the medium moves

  1. Along the z-axis

  2. Along the x-axis

  3. Along the y-axis

  4. In the x-y plane
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The particles of medium moves perpendicular to the direction of the propagation of the wave in the case of transverse wave.

In the given question, a transverse wave travels along z-axis. All the lines in the X-Y plane are perpendicular to z-axis, hence the particle of the medium must move in the X-Y plane.
The correct option is D.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

The particle displacement of a travelling longitudinal wave is represented by S=S (x,t). The midpoints of a compression zone and an adjacent rarefaction zone are represented by the letter 'C' and 'R' Which of the following is true?

  1. ${ \left| \partial S/\partial x \right| } _{ C }={ \left| \partial S/\partial x \right| } _{ R }$
  2. ${ \left| \partial S/\partial t \right| } _{ C }={ \left| \partial S/\partial t \right| } _{ R }=0$
  3. ${ \left( pressure \right) } _{ C }-{ \left( pressure \right) } _{ R }=2{ \left| \partial S/\partial x \right| } _{ C }x$ Bulk modulus of air.

  4. Particles of air are stationary mid-way between 'C' and 'R'.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In a longitudinal wave, the displacement gradient (dS/dx) represents the strain. At the center of a compression (C) and a rarefaction (R), the displacement is zero, but the magnitude of the strain (the slope of the displacement curve) is equal.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

Disturbance $y(x, t)$ of a wave propagating in the position x-direction is given by $y = \dfrac {1}{1 + x^{2}}$ at time $t = 0$ and by $y = \dfrac {1}{[1 + (x - 1^{2})]}$ at $t = 2\ s$, where $x$ and $y$ are in meters. The shape of the wave disturbance does not change during the propagation. The velocity of wave in m/s is

  1. $2.0$
  2. $4.0$
  3. $0.5$
  4. $1.0$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Comparing the wave function at t = 0 and t = 2, the disturbance shifts from f(x) to f(x - 1), which means the wave profile shifted by 1 meter in 2 seconds. The wave velocity is distance divided by time, which is 1 / 2 = 0.5 m/s.

Multiple choice physics properties of waves longitudinal and transverse waves travelling waves types of waves

In gases which wave cannot propagate

  1. standing wave

  2. longitudinal wave

  3. transverse wave

  4. none
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Transverse waves cannot propagate in gases because there are no forces to cause motion perpendicular to the direction of the wave. A transverse wave propagates in a solid because each atom of the solid has an "equilibrium location" where the forces on it from all its neighboring atoms balance. If one atom is pulled out of its equilibrium location by a disturbance, it will tend to be pulled back to that location. However, when it's out of its equilibrium location, it pulls its neighbors out of their equilibrium locations too, and so on down the line. The result is that a transverse wave disturbance propagates through the material.