Transverse & Longitudinal Waves

Q.

With the propagation of longitudinal waves through a medium, the quantity transmitted is

1. matter

2. energy

3. energy and matter

4. energy, matter, and momentum

Q. The maximum particle velocity is $3$ times the wave velocity of a progressive wave. If the amplitude of the particle is $a$, the phase difference between the two particles separated by a distance of ${}^{\prime }{x}^{\prime }$ is

1. $\frac{x}{a}$
2. $\frac{3x}{a}$
3. $\frac{3a}{x}$
4. $\frac{3\pi x}{a}$

Q.

How dark and bright fringes are formed?

Q.

A sine wave is traveling in a medium. The minimum distance between the two particles, always having same speed, is

1. $\frac{\lambda }{4}$

2. $\frac{\lambda }{3}$

3. $\frac{\lambda }{2}$

4. $\lambda$

Q. With the propagation of a longitudinal wave through a material medium, the quantities transmitted in the direction of propagation are:

1. Energy , momentum and mass
2. Energy
3. Energy and mass
4. Energy and linear momentum

Q. (a)Why are infra-red waves often called heat waves ? Explain.
(b) What do you understand by the statement, "Electromagnetic waves transport momentum" ?

Q.

Young’s Experiment Establishes That______.

1. Light Consists Of Waves

2. Light Consists Of Particles

3. Light Consists Of Both Particles And Waves

4. Light Consists Of Neither Particles Nor Waves

Q. Assertion: Longitudinal waves are called pressure waves.
Reason: Propagation of longitudinal waves through a medium involves changes in pressure in the medium.

1. Both assertion and reason are correct and reason is the correct explanation of assertion.
2. Assertion is incorrect but reason is correct.
3. Both assertion and reason are correct but reason is not a correct explanation of assertion.
4. Assertion is correct but reason is incorrect.

Q.

Is ultrasound a transverse wave?

Q.

What do you mean by electromagnetic spectrum? Give the complete electromagnetic spectrum.

Q.

Why are sound waves unable to be polarized?

Q. Assertion: Transverse mechanical wave does not travel in air.
Reason: Air has only bulk modulus of elasticity.

1. Both assertion and reason are correct and reason is the correct explanation of assertion.
2. Assertion is correct but reason is incorrect
3. Both assertion and reason are correct but reason is not a correct explanation of assertion
4. Assertion is incorrect but reason is correct

Q. When a longitudinal wave propagates through a medium, the particles of the medium execute simple harmonic oscillations about their mean positions. which of the following quantity remains invariant in these oscillations of the particle ?

1. Kinetic energy
2. Potential energy
3. Sum of kinetic energy and potential energy
4. Difference between kinetic energy and potential energy

Q.

Rank the following waves from fastest to slowest , Sound waves , water waves , light waves.

Q.

A wave going in a solid

1. must be longitudinal

2. may be longitudinal

3. must be transverse

4. may be transverse

Q. A transverse wave travels along the $z-$ axis. The particles of the medium must oscillate

1. along the $z-$ axis
2. in the $x-z$ plane
3. in the $y-z$ plane
4. in the $x-y$ plane

Q. The Bohr model for the spectra of a $H$-atom

1. will not be applicable to hydrogen in the molecular from.
   
2. is valid only at room temperature.
   
3. will not be applicable as it is for a $He$-atom.
   
4. ​​​​​​predicts continuous as well as discrete spectral lines.

Q. Even though an electric field $E$ exerts a force $qE$ on a charged particle yet the electric field of an EM wave does not contribute to the radiation pressure (but transfers energy). Explain.

Q. Which of the following options regarding a longitudinal wave is false.

1. Longitudinal wave can have a unique wavelength
2. Longitudinal wave can transmit energy
3. Longitudinal wave can have a unique velocity
4. Longitudinal wave can be polarized

Q.

A source of sound emits waves with frequency f Hz and speed V m/sec. Two

observers move away from this source in opposite directions each with a

speed 0.2 V relative to the source. The ratio of frequencies heard by the two

observers will be

1. 1 : 1

2. 4 : 10

3. 3 : 2

4. 2 : 3

Q. You are walking along a seashore and a mild wind is blowing. Is the motion of air a wave motion?

1. No

2. Yes

3. Depends on the direction of wind

4. Can't say

Q. Electromagnetic waves carry

1. positive charge
2. negative charge
3. energy
4. photons

Q.

What kind of waves are electromagnetic waves?

Q.

A wave moving in a gas

1. must be longitudinal

2. may be longitudinal

3. must be transverse

4. may be transverse

Q.

Match the following

1. Sound waves (i) Mechanical wave

2. Light waves (ii) Non-mechanical waves

3. Waves on a string (iii) Transverse waves

(iv) Longitudinal waves

1. 1 - (ii) (iv); 2 - (i) (iv); 3 - (ii) (iii)

2. 1 - (i) (iv); 2 - (ii) (iv); 3 - (ii) (iii)

3. 1 - (i) (iv); 2 - (ii) (iii); 3 - (i) (iii)

4. 1 - (ii) (iii); 2 - (i) (iii); 3 - (ii) (iv)

Q. Classically, an electron can be in any orbit around the nucleus of an atom. Then what determines the typical atomic size? Why is an atom not, say, thousand times bigger than its typical size? The question had greatly puzzled Bohr before he arrived at his famous model of the atom that you have learnt in the text. To simulate what he might well have done before his discovery, let us play as follows with the basic constants of nature and see if we can get a quantity with the dimensions of length that is roughly equal to the known size of an atom \((\sim 10^{-10} m)\).

You will find that the length (1/(4πε_0 ) e^2/mc^2 ) obtained as 2.8×〖10〗^(-15) " " m is many orders of magnitude smaller than the atomic dimensions. Further, it involves c. But energies of atoms are mostly in non-relativistic domain where c is not expected to play any role.
This is what may have suggested Bohr to discard c and look for ‘something else’ to get the right atomic size. Now, the Planck’s constant h had already made its appearance elsewhere. Bohr’s great insight lay in recognising that h, m_e , and e will yield the right atomic size.
Construct a quantity with the dimension of length from h, m_e, and e and confirm that its numerical value has indeed the correct order of magnitude

Q. Doppler’s effect does not depend upon

1. speed of source
2. speed of observer
3. frequency of sound
4. separation between source and listener

Q. Which of these will travel in a wave along with it?

1. both

2. none of these

3. particles

4. energy

Q. A longitudinal wave is propagating along $x-$ axis. Particles of the medium vibrates along

1. $x-$ axis
2. $y-$ axis
3. $z-$ axis
4. None of these

Q. A mechanical wave propagates in a medium along the X-axis. The particles of the medium

1. must move on the X-axis

2. must move on the Y-axis

3. may move on the X-axis

4. may move on the Y-axis