Chapter 11 PHYSICAL SCIENCE : Sound — Online MCQ Test
SCIENCE · CLASS 9th · Andhra State Board
Practice Chapter 11 PHYSICAL SCIENCE : Sound with a free chapter-wise online MCQ test.
This chapter covers: This chapter covers sound production propagation wave nature velocity reflection sonar human ear structure and audible frequency ranges..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 11 PHYSICAL SCIENCE : Sound — Important Questions & Answers
What is the production of sound in humans called?
- A. Vibration of vocal cords
- B. Reflection of sound
- C. Echo
- D. Absorption of sound
Answer: A. Vibration of vocal cords
Human beings produce sound when the vocal cords vibrate. These vibrations create sound waves in the air.
Human beings produce sound when the vocal cords vibrate. These vibrations create sound waves in the air.
Sound travels fastest through which medium?
- A. Air
- B. Vacuum
- C. Water
- D. Steel
Answer: D. Steel
Sound travels fastest in solids because particles are closely packed. Among the given options, steel is the fastest medium.
Sound travels fastest in solids because particles are closely packed. Among the given options, steel is the fastest medium.
Which of the following is a longitudinal wave?
- A. Light wave
- B. Water ripple only
- C. Sound wave in air
- D. Radio wave
Answer: C. Sound wave in air
Sound waves in air travel by compressions and rarefactions, so they are longitudinal waves. Light and radio waves are electromagnetic waves.
Sound waves in air travel by compressions and rarefactions, so they are longitudinal waves. Light and radio waves are electromagnetic waves.
Which of the following statements is NOT correct about sound waves?
- A. They can travel through solids, liquids and gases
- B. They require a material medium
- C. They are always transverse waves
- D. They can be reflected
Answer: C. They are always transverse waves
Sound waves in air are longitudinal, not always transverse. The other statements are correct properties of sound.
Sound waves in air are longitudinal, not always transverse. The other statements are correct properties of sound.
A sonar device sends a pulse and receives its echo after 4 seconds. If the speed of sound in water is 1500 m/s, what is the depth of the sea?
- A. 1500 m
- B. 3000 m
- C. 6000 m
- D. 7500 m
Answer: B. 3000 m
The pulse travels to the bottom and back, so depth = (speed × time) / 2. Thus, depth = (1500 × 4) / 2 = 3000 m.
The pulse travels to the bottom and back, so depth = (speed × time) / 2. Thus, depth = (1500 × 4) / 2 = 3000 m.