Very Short Answer Questions - 1 Mark

Q1. What does wave transfer-matter or energy?

Ans. Energy

Q2. What are mechanical waves?

Ans. Waves that are characterised by the motion of particles in a medium are called mechanical waves. Mechanical waves require material medium for their propagation.

Q3. Where is the density of air higher-at compressions or at rarefactions?

Ans. At compressions.

Q4. What is one complete oscillation?

Ans. The change in density from one maximum value to the minimum value and again to the maximum value makes one complete oscillation.

Q5. On what factor does the pitch of a sound depend?

Ans. The pitch of a sound depends on the frequency of vibrations. Actually, the pitch of a sound is directly proportional to its frequency

Q6. What is the wavelength in the given curve?

Ans. AE

Q7. If any explosion takes place at the bottom of a lake, what type of shock waves in water will take place?

Ans. Longitudinal waves.

Q8. What is intensity of sound?

Ans. The amount of sound energy passing through unit area each second is called the intensity of sound.

Q9. What is relation between time period and frequency?

Ans. Frequency

Q10. Name two animals that communicate using infrasound

Ans. Rhinoceroses and whales communicate using infrasound.

Q11. Name the sound waves used by bats while flying in the dark.

Ans. Bats use ultrasonic waves while flying in the dark.

Q12. Earthquake produces which kind of sound before the main shock wave begins?

Ans. Infrasound.

Q13. Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, what is he adjusting?

Ans. He is adjusting frequency of the sitar string with the frequency of the other musical instruments.

Q14. Name the characteristic which helps us to distinguish between a man's voice and a woman's voice, even without seeing them.

Ans. Quality or timbre.