Audible and Inaudible Sounds MCQs
Audible and Inaudible Sounds – MCQs with Answers & Explanations
Class: 8 |
Subject: Science
Section: 13 – Sound
Topic: Audible and Inaudible Sounds
Board: CBSE Board Examination (Based on NCERT Syllabus)
Section: 13 – Sound
Topic: Audible and Inaudible Sounds
Board: CBSE Board Examination (Based on NCERT Syllabus)
1. Audible sounds are those which:
Answer: B — Can be heard by humans
Audible sounds fall within the human hearing range and can be detected by our ears.
Audible sounds fall within the human hearing range and can be detected by our ears.
2. Human audible range is:
Answer: B — 20–20,000 Hz
Humans can hear sounds only within this frequency range.
Humans can hear sounds only within this frequency range.
3. Sounds below 20 Hz are called:
Answer: C — Infrasonic
These very low-frequency sounds cannot be heard by humans but are detected by animals like elephants.
These very low-frequency sounds cannot be heard by humans but are detected by animals like elephants.
4. Sounds above 20,000 Hz are:
Answer: C — Ultrasonic
Ultrasonic sounds have very high frequency and are inaudible to humans.
Ultrasonic sounds have very high frequency and are inaudible to humans.
5. Which animal can hear ultrasonic sounds?
Answer: B — Dog
Dogs can detect ultrasonic frequencies, which is why dog whistles work.
Dogs can detect ultrasonic frequencies, which is why dog whistles work.
6. Elephants communicate using:
Answer: B — Infrasonic sound
Low-frequency infrasonic waves travel long distances, helping elephant communication.
Low-frequency infrasonic waves travel long distances, helping elephant communication.
7. Ultrasonic waves are used in:
Answer: B — Medical imaging
Ultrasound scans help doctors view internal organs safely.
Ultrasound scans help doctors view internal organs safely.
8. Bats navigate using:
Answer: B — Ultrasonic sound
Bats use echolocation with ultrasonic waves.
Bats use echolocation with ultrasonic waves.
9. Inaudible sounds are those:
Answer: B
Outside human hearing range.
Outside human hearing range.
10. Dog whistle produces:
Answer: B
Heard by dogs, not humans.
Heard by dogs, not humans.
11. Unit of frequency:
Answer: B
12. Ultrasonic cleaning is used for:
Answer: B
Cleans delicate items.
Cleans delicate items.
13. SONAR uses:
Answer: B
14. Human cannot hear:
Answer: C
15. Example of infrasonic source:
Answer: A
16. Audible sound lower limit:
Answer: B
17. Audible sound upper limit:
Answer: C
18. Ultrasound scanning is safe because it uses:
Answer: B
19. Bats detect obstacles using:
Answer: B
20. Inaudible sounds include:
Answer: A
Both ranges are inaudible to humans.
Both ranges are inaudible to humans.
