Tag: physics

Questions Related to physics

Sound does not exhibit the property of

physics study of sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. Reflection

  2. Doppler Effect

  3. Diffraction

  4. Polarization

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Correct Option: D
Explanation:

Polarization is exhibited only by Transverse waves. Sound waves being longitudinal do not exhibit this phenomenon. 

A uniform tub to length $60.5\,cm$ is held vertically with its lower end dipped in water. A sound source of frequency $500\,Hz$ sends sound waves into the tube. When it is $50\,cm$, the tube resonates with the source of sound. Two lowest frequencies (in Hz), to which tube will resonate when it is taken out of water, are (approximately)

physics study of sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. $281, 562$

  2. $281, 843$

  3. $276, 522$

  4. $272, 544$

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Correct Option: C

If wind blows in a direction opposite to the sound propagation, then the velocity of the sound

physics study of sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. increases

  2. decreases

  3. remains constant

  4. Cannot be determined

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Correct Option: B

A replica of longitudinal waves can be best observed 

physics study of sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. by swinging a pendulum

  2. by pressing and releasing a horizontal spring

  3. by striking a guitar string

  4. by rotating a top

Show answer
Correct Option: B
Explanation:

If we press and release a horizontal spring, it exhibits a confined motion of compression and rarefaction. So, it shows a replica of longitudinal waves. A swinging pendulum performs simple harmonic motion. A struck guitar string exhibits a replica of transverse waves. A rotating top exhibits rotational motion.

Sound waves in air are

physics study of sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. transverse

  2. longitudinal

  3. electromagnetic

  4. polarised

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Correct Option: B
Explanation:

Sound waves are longitudinal waves because the disturbance of the medium particles is parallel to the direction of propagation of wave. The compression and rarefraction pulses produced moves in the direction parallel to the propagation direction of wave.

A tuning fork is excited by striking it with a padded hammer. What would be the nature of the vibrations executed by the prongs as well as the stem of the fork respectively ? (The reference direction is that of the propagation of the sound wave.)

physics study of sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. Both vibrate longitudinally

  2. Both vibrate transversely

  3. The prong vibrate longitudinally whereas the stem vibrates transversely

  4. The prong vibrate transversely whereas the stem vibrates longitudinally

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Correct Option: C

The ratio of the velocity of body and velocity of sound is known as

physics propagation of sound waves sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. laplace number

  2. positive number

  3. stable number

  4. mach number

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Correct Option: D
Explanation:

Definition of Mach Number is $Ma=\frac{V _{body}}{V _{\mbox{sound in that medium}}}$.
Option "D" is correct.

Sound wave are not polarized because:

physics sound sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. Their speed is less

  2. A medium is needed for their propagation

  3. These are longitudinal

  4. Their speed depends on temperature

Show answer
Correct Option: A
Explanation:
   Sound wave are not polarized because,their speed is less.So the option is A.

The ratio of the speed of a body to the speed of sound is called:

physics propagation of sound waves sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. Mach number

  2. Doppler Ratio

  3. Sonic index

  4. Refractive index

Show answer
Correct Option: A
Explanation:

Mach number of a body is the ratio of its speed to that of local sound.
The local speed of sound, and thereby the Mach number, depends on the condition of the surrounding medium, in particular the temperature and pressure. The Mach number is primarily used to determine the approximation with which a flow can be treated as an incompressible flow. 

Which type of wave is produced in the stem of tuning fork?

physics vibrations of stretched strings sound as a wave of disturbance vibrations in a tuning fork vibrations in tuning fork

  1. transverse

  2. transverse stationary

  3. longitudinal

  4. longitudinal stationary

Show answer
Correct Option: C
Explanation:

When tuning fork is sounded by striking its one end on rubber pad then the prongs vibrate in and out and stem vibrate up and down. Hence, vibration of prongs are transverse and those of stem are longitudinal.