Tag: physics

Questions Related to physics

In an auditorium or big hall excessive reverberation is highly _______.

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. undesirable

  2. desirable

  3. zero

  4. none of the above

Show answer
Correct Option: A
Explanation:

Sound created in a big hall will persist  by repeated reflection from the walls until it is reduced to a value where it is no longer audible. The repeated reflection that results in this persistence of sound is called reverberation. In an auditorium or big hall excessive reverberation is highly undesirable.

If the ceiling of a cinema is made flat, what will happen?

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. No sound will be audible at all

  2. Picture will vanish

  3. Sound will not reach properly to every person

  4. Pictures will not be clear to everyone

Show answer
Correct Option: C
Explanation:

Ceiling in a cinema hall is made curve so that the sound of music, dialogue etc must reach evenly to all the audience. So that the sound after reflection from the curved surface reaches all corners of the hall evenly.

Reverberation time of a hall used for speeches should be very short. Otherwise

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. multiple echos will enhance the sound quality

  2. multiple echos will interfere with the original sound

  3. multiple echos will not interfere with the original sound 

  4. both A and B

Show answer
Correct Option: B
Explanation:

Reverberation time of a hall used for speeches should be very short because multiple echoes will interfere with the original sound. So, reverberation time is reduced to avoid multiple echoes.

Why do we hear more clearly in a room with curtains than in a room without curtains? 

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. sound is absorbed by the curtains

  2. less reverberation without curtains

  3. high reverberation without curtains

  4. both A and B

Show answer
Correct Option: B
Explanation:

There is more reverberation in rooms with curtains so we can hear sound more clearly.

Mark the correct statement :

i)rock music also becomes less pleasing with excessive reverberation.
ii)excessive reverberation is desirable in case of orchestral and choral music. 
iii)excessive reverberation makes the speech of a person indistinct. 

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. i, ii

  2. ii, iii

  3. i, iii

  4. All of them

Show answer
Correct Option: D
Explanation:

A certain amount of reverberation may improve the quality of sound. However, excessive reverberation is sometimes undesirable as it interferes with the original sound and hence makes the speech or music indinstict

Mark the correct match

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. Good reflectors of sound-Tiles, Marble slabs

  2. Bad reflectors of sound - Thick curtains, thick carpets

  3. Good absorbers of sound - Holed cardboard

  4. All

Show answer
Correct Option: D
Explanation:

Sound is not reflected equally from different materials. Hard surfaces reflects more sound.
Bad reflectors of sound are good absorbers. Soft thick curtains, thick carpets, holed card boards are examples of good absorbers of sound.

Identify the device which work on the reflection of sound.

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. Megaphone

  2. Stethoscope

  3. Sound boards

  4. All of the above

Show answer
Correct Option: D
Explanation:

Megaphone, Stethoscope and Sound boards work on the reflection of sound.

$1.$Megaphone is a portable, cone shaped acoustic horn used to amplify a person's voice or other sounds and direct it in a given direction.
$2.$Stethoscope is an acoustic medical device for listening to the internal sounds of an animal or human body.
$3.$Sound board is the surface of a string instrument that the string vibrate against.

Which of the following are examples of multiple reflections of sound?

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. Stethoscope

  2. Sound board

  3. Megaphone

  4. All of the above

Show answer
Correct Option: D
Explanation:

Process in which sound waves bounces off obstacles and reflects many times before reaching destinations is known as multiple reflection of sound, So, all of the above are examples of multiple reflections of sound

What is multiple reflection of sound?

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. Process in which sound waves bounces off obstacles and reflects many times before reaching destinations

  2. Process in which sound waves penetrates in obstacles and reflects many times before reaching destinations

  3. Process in which sound waves bounces off obstacles and deflects one time before reaching destinations

  4. None

Show answer
Correct Option: A
Explanation:

Process in which sound waves bounces off obstacles and reflects many times before reaching destinations is known as multiple reflection of sound

The persistence of audible sound due to the successive reflections from the surrounding objects even after the source has stopped to produce that sound is called _________.

physics study of sound reverberation applications of reflection of sound multiple reflection of sound and reverberation applications of ultrasound

  1. reflection

  2. echo

  3. reverberation

  4. rarefaction

Show answer
Correct Option: C
Explanation:

In big rooms or halls,echos (due to multiple reflection of sound from the walls, roof, floor) follow so closely behind the original sound that the original sound appears to be prolonged even when the source of sound stops producing sound.