Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

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

A metal hammer hits a spherical bell, when the circuit in a calling bell is switched ON, the propogation of sound takes place due to 

  1. Air

  2. electric current

  3. metal bell

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Though the hammer strikes the bell and the bell starts vibrating, these vibrations are then carried out to the atmosphere only by air molecules thereby creating a sound

The correct option is (a)

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

Two small boats are $10m$ apart on a lake. Each pops up and down with a period of $4.0 seconds$ due to wave motion on the surface of water. When one boat is at its highest point, the other boat is at its lowest point. Both boats are always within a single cycle of the waves. The speed of the waves is:

  1. $2.5m/s$
  2. $5.0m/s$
  3. $14m/s$
  4. $40m/s$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The distance between a crest and a trough is half a wavelength (lambda/2). Given 10m = lambda/2, the wavelength lambda is 20m. Using the wave speed formula v = lambda / T, where T = 4.0s, we get v = 20m / 4.0s = 5.0m/s.

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
B Correct answer