Class 8 Sound CBSE Questions & Answers

Class 8 · Sound

This is Science Class 8 Sound CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Which of the following species use ultrasound for navigation and catching prey?
  • A
    Cat
  • B
    Bats
    Correct
  • C
    Cow
  • D
    Owl
2
Infrasound have frequency
  • A
    More than 20Hz
  • B
    More than 20,000Hz
  • C
    Less than 20Hz
    Correct
  • D
    Equal to 20,000Hz
3
Motion of which of these object is known as periodic motion?
  • A
    Aeroplane
  • B
    Train
  • C
    Pendulum
    Correct
  • D
    Flying bird
4
What is the name of motion when an object repeats its motion after some time?
  • A
    Curvilinear motion
  • B
    Periodic motion
    Correct
  • C
    Rectilinear motion
  • D
    Circular motion
5
Loudness of sound is measured in
  • A
    Micron
  • B
    Hertz
  • C
    Decibel
    Correct
  • D
    Micrometer
6
The of object greater than speed of sound in air is called
  • A
    Supersonic
    Correct
  • B
    Audible
  • C
    Infrasonic
  • D
    Ultrasonic
7
Which of the following travels slowest in air?
  • A
    Sound
  • B
    Ultrasound
  • C
    Light
  • D
    Aircraft
    Correct
8
Dolphins and whales communicate by
  • A
    All of these
  • B
    Propagation of sound through air
  • C
    Propagation of sound through water
    Correct
  • D
    Propagation of waves through air
9
Speed of sound in air is about
  • A
    750m/s
  • B
    1500m/s
  • C
    5000m/s
  • D
    334m/s
    Correct
10
The device used to produce sound in laboratory experiment is called
  • A
    Speedometer
  • B
    Sound meter
  • C
    Hertz
  • D
    Tuning fork
    Correct
11
Motion described by a simple pendulum is called
  • A
    Oscillatory motion
    Correct
  • B
    Periodic motion
  • C
    Rotatory motion
  • D
    Rectilinear motion
12
Vocal chord vibrates when
  • A
    Diaphragm relax
  • B
    Lungs contracts
  • C
    Lung force air into heart
  • D
    Lung force air through slit
    Correct
13
The region of high density during propagation of sound is called
  • A
    Compression
    Correct
  • B
    Crest
  • C
    Rarefaction
  • D
    Trough
14
During propagation of sound air particles
  • A
    Moves only in forward direction
  • B
    Vibrate back and forth
    Correct
  • C
    Moves only in backward direction
  • D
    Moves from source to receiver
15
How many vocal chords are stretched across the voice box?
  • A
    More than four
  • B
    Four
  • C
    Two
    Correct
  • D
    Three