Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Sound — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
25 × 1 = 25 marks
1.
Sound is produced by objects that:
- A.Glow
- B.Vibrate
- C.Melt
- D.Float
2.
In humans, sound is produced by the:
- A.Lungs
- B.Vocal cords
- C.Heart
- D.Stomach
3.
Sound travels through a medium in the form of:
- A.Light rays
- B.Waves
- C.Heat only
- D.Magnets
4.
Sound cannot travel through a:
- A.Solid
- B.Liquid
- C.Gas
- D.Vacuum
5.
The bell-in-a-jar experiment shows that sound needs a:
- A.Battery
- B.Medium to travel
- C.Light source
- D.Magnet
6.
The loudness of a sound depends on its:
- A.Frequency
- B.Amplitude
- C.Quality
- D.Speed
7.
The pitch of a sound depends on its:
- A.Amplitude
- B.Frequency
- C.Loudness
- D.Colour
8.
Frequency is measured in:
- A.Decibel
- B.Hertz
- C.Newton
- D.Pascal
9.
A higher frequency produces a sound of:
- A.Lower pitch
- B.Higher pitch
- C.Less loudness
- D.More amplitude
10.
The characteristic that lets us tell a flute from a violin is:
- A.Loudness
- B.Pitch
- C.Quality (timbre)
- D.Speed
11.
Sound travels fastest through:
- A.Gases
- B.Liquids
- C.Solids
- D.Vacuum
12.
The approximate speed of sound in air is:
- A.34 m/s
- B.340 m/s
- C.3400 m/s
- D.3 m/s
13.
The repetition of a sound due to reflection is called a/an:
- A.Vibration
- B.Echo
- C.Pitch
- D.Frequency
14.
We see lightning before hearing thunder because:
- A.Sound is faster
- B.Light travels much faster than sound
- C.Thunder comes first
- D.Light is slower
15.
SONAR and ultrasound scans are based on the ______ of sound.
- A.Production
- B.Reflection
- C.Absorption only
- D.Colour
16.
The human audible range of frequencies is about:
- A.2–20 Hz
- B.20–20,000 Hz
- C.20,000–40,000 Hz
- D.1–10 Hz
17.
Sound with a frequency below 20 Hz is called:
- A.Audible
- B.Infrasonic
- C.Ultrasonic
- D.Echo
18.
Sound with a frequency above 20,000 Hz is called:
- A.Audible
- B.Infrasonic
- C.Ultrasonic
- D.Loud
19.
Which animal uses ultrasonic sound to navigate in the dark?
- A.Elephant
- B.Bat
- C.Whale
- D.Cow
20.
A "silent" dog whistle works because it produces:
- A.Infrasound humans hear
- B.Ultrasound dogs hear but humans don't
- C.A bright light
- D.No sound at all
21.
The presence of excessive or unwanted harmful sound is called:
- A.Music
- B.Noise pollution
- C.Echo
- D.Vibration
22.
Which of these is a major source of noise pollution?
- A.Trees
- B.Vehicle horns
- C.Sunlight
- D.Rain only
23.
A harmful effect of noise pollution on health is:
- A.Better sleep
- B.Loss of hearing
- C.Improved focus
- D.More energy
24.
A sound that is unpleasant or unwanted is called a:
- A.Musical sound
- B.Noise
- C.Echo
- D.Pitch
25.
Planting trees along roads helps to:
- A.Increase noise
- B.Absorb and reduce noise
- C.Produce sound
- D.Block sunlight only
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Vibrate
- (B) Vocal cords
- (B) Waves
- (D) Vacuum
- (B) Medium to travel
- (B) Amplitude
- (B) Frequency
- (B) Hertz
- (B) Higher pitch
- (C) Quality (timbre)
- (C) Solids
- (B) 340 m/s
- (B) Echo
- (B) Light travels much faster than sound
- (B) Reflection
- (B) 20–20,000 Hz
- (B) Infrasonic
- (C) Ultrasonic
- (B) Bat
- (B) Ultrasound dogs hear but humans don't
- (B) Noise pollution
- (B) Vehicle horns
- (B) Loss of hearing
- (B) Noise
- (B) Absorb and reduce noise
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