CBSE Class 8 Science Chapter 10 Sound Very Short Answer Questions
Question 1. Does any part of our body vibrate when we speak? Name the part.
Answer: Yes, while speaking, the part that vibrates is called the vocal cords. It is below the throat and creates vibrations while speaking.
Question 2. Explain how you can describe vocal cords.
Answer: The two ligaments which stretch across the larynx in such a way that it leaves a narrow slit between them for the passage ofair, are known as vocal cords.
Read And Learn More CBSE Class 8 Science Very Short Questions And Answers
Question 3. Name two musical instruments that produce sound by vibrating strings.
Answer: The Guitar and sitar are two musical instruments that produce sound by vibrating strings.
” Cbse Class 8 Science Chapter 10 Vsaqs “
Question 4. Why do we not hear the sound of an explosion on the surface of the moon?
Answer: There is no atmosphere on the moon, and sound waves need a medium to travel, so we cannot hear sound on the moon.
Question 5. How do whales and dolphins hear sound?
Answer: Through water as a liquid medium, both whales and dolphins hear the sound
Question 6. When we hear a sound, does any part of our body
Answer: It is the eardrum that vibrates and sends vibrations to the inner ear when we hear any sound.
” Sound Very Short Answer Questions Class 8 “
Question 7. A baby recognises her mother by her voice. Name the characteristic of sound involved.
Answer: Pitch is that characteristic of sound by which distinction can be made between two sounds.
Question 8. What is the frequency of a wave with a period of 0.025 s?
Answer: Given, T =0.025 s,
⇒ \(\mathrm{v}=\frac{1}{T}=\frac{1}{0.025}=40 \mathrm{~Hz}\)
” Sound Propagation Through Medium “
Question 9. Different bees produce buzzing sounds of different pitches. Which affects the pitch of the bee’s buzzing sound?
Answer: The faster the bee vibrates its wings, rthe greater the frequency of the sound and the frequency of sound. Hence, the higher the frequency, the more will he the pitch.
Question 10. Our steps do not produce a loud sound if we walk on a carpet floor. Explain with the help of a reason.
Answer: As the amplitude of vibrations of the floor is reduced and the sound ot our steps becomes feeble, so due to this reason, we do not produce a loud sound when we walk on a dry carpet floor.
” Vocal Cords And Sound Production “
Question 11. Mention the name given to the maximum displacement of a vibrating body from its central position.
Answer: Amplitude is a name given to the maximum displacement of a vibrating body from its central position.
Question 12. Explain why babies have a feeble sound.
Answer: Due to the small amplitude of their sound, babies have a teething sound
Question 13. Three different vibrating objects produce three types of sounds, X, V, and Z. The sounds X and Y cannot be heard by a man having a normal range of hearing, but sound Z can be heard easily. The sound X can be heard by a bat, whereas sound Y can be heard by a rhinoceros. What type of sounds are X, Y, and Z?
Answer: X is ultrasonic sound, Y is infrasonic sound, and Z is audible sound.
” Musical Instruments With Vibrating Strings “
Question 14. Lightning can be seen at the moment when it occurs. Paheli observes lightning in her area. She hears the sound 5 s after she observed lightning. How far is she from the place where lightning occurs? (Speed of sound =330 m/s)
Answer: We know that,
- Distance = Speed x Time = 330 x 5 =1650 m
- = 1.65 km (Y 1 km =1000 m)
- So, she is standing 1.65 km from the place where the lightning occurs.
Question 15. A hearing aid that is attached to the ear helps people who suffer from hearing loss. What is the main function of the hearing aid?
Answer: The hearing aid amplifies the sound received from the surroundings.