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
When the amplitude is doubled than its loudness
  • A
    Decrease 4 times
  • B
    Increase 4 times
    Correct
  • C
    Decrease 2 times
  • D
    Increase 2 times
2
Which of the following vibrates with a low frequency?
  • A
    Drum
    Correct
  • B
    Sitar
  • C
    Whistle
  • D
    Flute
3
Industrial noise can be reduced by
  • A
    Shutting down all industrial activity
  • B
    Removing all persons away from factories
  • C
    Installing industrial activity away from residential area
    Correct
  • D
    Not using machine that produce noise
4
The frequency of a sound wave is 200 Hz, how many times will it vibrates in one minute?
  • A
    6,000 times
  • B
    4,000 times
  • C
    200 times
  • D
    12,000 times
    Correct
5
Which of the following quantities are proportional to each other?
  • A
    Frequency and wavelength
  • B
    All of the above
  • C
    Amplitude and loudness
    Correct
  • D
    Time-period and frequency
6
We are not able to hear the sound of pendulum although it is oscillating because
  • A
    Frequency is more than 20,000Hz
  • B
    Wavelength is very less
  • C
    Frequency is more than 10 Hz
  • D
    Frequency is less than 10Hz
    Correct
7
Sound travels faster in solid medium as compared to liquid and gases because
  • A
    Particles moves easily
  • B
    Particles of solid are very close
    Correct
  • C
    Intermolecular force is weak
  • D
    Particles are away from each other
8
Loudness of sound is proportional to
  • A
    Amplitude
  • B
    Square of frequency
  • C
    Square of the amplitude
    Correct
  • D
    Frequency
9
A person is exposed to a loud sound continuously he may get
  • A
    Optical problems and swelling of pinna
  • B
    High blood pressure and goiter
  • C
    Skin disease and heart disease
  • D
    Temporary or permanent impairment of hearing
    Correct
10
Total hearing impairment is usually
  • A
    Due to minor accident
  • B
    Due to unhygienic condition
  • C
    Due to viewing TV at high volume
  • D
    From birth
    Correct
11
In a classroom, all the students speak together the sound produced will be called
  • A
    Music
  • B
    Noise
    Correct
  • C
    Pleasing sound
  • D
    Soothing sound
12
Sound cannot be heard directly on moon because
  • A
    Hydrogen gas is present on moon
  • B
    There is no air on moon
    Correct
  • C
    Moon is a non-luminous body
  • D
    Moon has uneven surface
13
The relation between speed of sound, frequency and wavelength is
  • A
    Frequency = speed x speed
  • B
    All of these
  • C
    Speed = frequency × wavelength
    Correct
  • D
    Wavelength = frequency x speed
14
Speed of sound in sea water is slightly more than distilled water because
  • A
    Density of sea water is more
    Correct
  • B
    Density of distilled water is more
  • C
    Sea is larger in size
  • D
    Density of sea water is less
15
If the thunder is heard by a man 4 seconds after the lightening is seen. How far is the lightening from man? (Speed of sound in air is 330m/s )
  • A
    330 m
  • B
    1420 m
  • C
    1320 m
    Correct
  • D
    1230 m