Sound MCQs Class 8 Science
Sound MCQs Class 8 Science
Class: 8 |
Subject: Science
Section: 13 – Sound
Topic: Sound MCQs with Answers & Explanations
Based on: CBSE Board Examination (NCERT Syllabus)
Section: 13 – Sound
Topic: Sound MCQs with Answers & Explanations
Based on: CBSE Board Examination (NCERT Syllabus)
1. Sound is produced due to:
Answer: B — Vibrations of objects
Sound is generated when an object vibrates. These vibrations disturb surrounding particles, producing sound waves that travel through a medium.
Sound is generated when an object vibrates. These vibrations disturb surrounding particles, producing sound waves that travel through a medium.
2. Which of the following is NOT a medium for sound?
Answer: C — Vacuum
Sound requires particles to travel. In vacuum, there are no particles, so sound cannot propagate.
Sound requires particles to travel. In vacuum, there are no particles, so sound cannot propagate.
3. The to-and-fro motion of an object is called:
Answer: B — Oscillation
Oscillation refers to repeated back-and-forth motion about a mean position, essential for sound production.
Oscillation refers to repeated back-and-forth motion about a mean position, essential for sound production.
4. Sound travels fastest in:
Answer: C — Solids
Particles in solids are closely packed, enabling faster transmission of vibrations compared to liquids and gases.
Particles in solids are closely packed, enabling faster transmission of vibrations compared to liquids and gases.
5. Human ear can hear frequencies between:
Answer: B — 20–20,000 Hz
This is the audible range. Below 20 Hz is infrasonic; above 20,000 Hz is ultrasonic.
This is the audible range. Below 20 Hz is infrasonic; above 20,000 Hz is ultrasonic.
6. Loudness of sound depends on:
Answer: B — Amplitude
Greater amplitude means more energy and louder sound.
Greater amplitude means more energy and louder sound.
7. Pitch of sound depends on:
Answer: B — Frequency
Higher frequency produces higher pitch (shrill sound).
Higher frequency produces higher pitch (shrill sound).
8. Unit of frequency is:
Answer: B — Hertz
1 Hertz = 1 vibration per second.
1 Hertz = 1 vibration per second.
9. Echo is caused by:
Answer: B — Reflection
Sound waves bounce back from surfaces producing echo.
Sound waves bounce back from surfaces producing echo.
10. Minimum distance to hear echo distinctly is about:
Answer: C — 17 m
This ensures a 0.1 s gap required for the ear to distinguish reflected sound.
This ensures a 0.1 s gap required for the ear to distinguish reflected sound.
11. Device used to measure loudness:
Answer: B — Audiometer
It measures hearing ability and sound intensity levels.
It measures hearing ability and sound intensity levels.
12. Unwanted sound is called:
Answer: B — Noise
Noise is unpleasant and harmful to hearing.
Noise is unpleasant and harmful to hearing.
13. Excessive noise causes:
Answer: B — Noise pollution
It leads to stress, sleep disturbance, and hearing loss.
It leads to stress, sleep disturbance, and hearing loss.
14. Ultrasonic sounds are used in:
Answer: B — SONAR
SONAR uses ultrasonic waves to detect underwater objects.
SONAR uses ultrasonic waves to detect underwater objects.
15. Time taken for one vibration:
Answer: C — Time period
It is the inverse of frequency.
It is the inverse of frequency.
16. Shrillness is related to:
Answer: B — Pitch
Higher pitch → more shrill sound.
Higher pitch → more shrill sound.
17. Sound cannot travel through:
Answer: D — Vacuum
No particles → no vibration transfer.
No particles → no vibration transfer.
18. Larger amplitude produces:
Answer: B — Loud sound
Amplitude controls loudness.
Amplitude controls loudness.
19. Sound travels in the form of:
Answer: B — Waves
Sound propagates as mechanical waves.
Sound propagates as mechanical waves.
20. Noise level is measured in:
Answer: C — Decibel
Decibel (dB) measures sound intensity and noise pollution levels.
Decibel (dB) measures sound intensity and noise pollution levels.
