Tag: study of sound

Quizzes (14) Questions (314)

Questions Related to study of sound

Multiple choice physics study of sound types of waves sound as a wave of disturbance sound waves are longitudinal waves

Which of the following statements is true?

  1. Pressure undergoes no change at the nodes in the case of longitudinal stationary waves

  2. Pressure is minimum at the nodes in the case of longitudinal stationary waves

  3. Pressure is maximum at nodes in the case of longitudinal stationary waves

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

At nodes in longitudinal waves,there is maximum compression, So, there will be pressure.

Multiple choice physics study of sound types of waves sound as a wave of disturbance sound waves are longitudinal waves

When source and detector are stationary but the wind is blowing at speed ${ v } _{ w }$, the apparent wavelength ${ \lambda  }'$ on the wind side is related to actual wavelength ${ \lambda  }$ by [take speed of sound in air as v]

  1. ${ \lambda }'={ \lambda }$
  2. ${ \lambda }'=\frac { { v } _{ w } }{ v } \lambda $
  3. ${ \lambda }'=\frac { { v } _{ w }+v }{ v } \lambda $
  4. ${ \lambda }'=\frac { v }{ v-{ v } _{ w } } \lambda $
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The apparent speed of sound with wind is (v + vw). The frequency f remains constant. Since v_apparent = f * lambda_prime, we have (v + vw) = f * lambda_prime. Since v = f * lambda, f = v/lambda. Thus, lambda_prime = (v + vw) / (v/lambda) = ((v + vw) / v) * lambda.

Multiple choice physics study of sound types of waves sound as a wave of disturbance sound waves are longitudinal waves

Assertion - Sound wave is an example of longitudinal wave.
Reason - In longitudinal waves, the constituents of the medium oscillate perpendicular to the direction of wave propagation.

  1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

  2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

  3. Assertion is correct but Reason is incorrect

  4. Both Assertion and Reason are incorrect
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A sound wave is an example of the longitudinal wave.
But in longitudinal waves, the constituents of the medium oscillate parallel to the direction of wave propagation. So sound wave is an example of longitudinal wave.

Multiple choice physics study of sound conditions for hearing echo echo ultrasound and its applications

An echo will be heard if the minimum distance between the source of sound and the obstacle is :

[assume air to be the medium]

  1. $1\;m$
  2. $10\;m$
  3. $15\;m$
  4. $17\;m$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

As the sensation of sound persists in our brain for about 0.1 s, to hear a distinct echo the time interval between the original sound and the reflected one must be at least 0.1 s. If we take the speed of the sound to be 344 m/s at a given temperature, say at 22 $^0 C $ in air, sound must go to the obstacle and reach back the ear of the listener on reflection after 0.1 s. 


Hence, the total distance covered by the sound from the point if generation to
the reflecting surface and back should be at least 

$344 \times 0.1= 34.4 m.$

Thus for hearing distinct echoes, the minimum distance pf the obstacle from 
the source of sound must be half this distance

That is, $\frac{34.4}{2}=17.2\,m \approx 17\,m$

Multiple choice physics study of sound conditions for hearing echo echo ultrasound and its applications

Bats detect the obstacle in their path by receiving the detected

  1. Infrasonic waves

  2. Ultrasonic waves

  3. Both

  4. None
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Bats can produce ultrasonic waves by flapping their wings. They can also detect these waves.these waves produced by the bats after reflection from the obstacles like building guide them to  remain away from the obstacles during night with the help of ultrasonic waves.

Multiple choice physics study of sound conditions for hearing echo echo ultrasound and its applications

The technique used by bats to find their way or to locate food is _______.

  1. SONAR

  2. RADAR

  3. Echolocation

  4. Flapping
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Bats can produce ultrasonic waves by flapping their wings. They can also detect these waves.these waves produced by the bats after reflection from the obstacles like building guide them to  remain away from the obstacles during night with the help of ultrasonic waves.