Reflection of Sound

Q.

White some applications of reflection of sound waves.

Q.

Give two practical applications of reflection of sound waves.

Q.

What are the properties and applications of ultrasound?

Q. What is the major difference between echo and reverberation?

Q.

How is it that bats are able to fly at night without colliding with other objects ?

Q.

Write the differences between light 💡 wave 🌊 and sound 🔊 wave 🌊 .

Q.

Name the device used by doctors to listen to our heartbeats.

Q.

What is the range of frequencies associated with infrasound and ultrasound?

Q.

Why echoes can't be heard in a small room?

1. Because small rooms absorb more sound.

2. Because time gap between direct sound and reflected sound is too low to be perceptible by human ear.

3. Because small rooms reflect less amount of energy.

4. Because of multiple reflections in small rooms.

Q.

(a) What is meant by 'reflection of sound' ? What type of surfaces are the best for reflecting sound ?

(b) Name any two objects which are good reflectors of sound.

(c) State the laws of reflection of sound.

Q.

Name three devices which work on the reflection of sound.

Q. Question 16
For hearing the loudest ticking sound heard by the ear, find the angle x in the Figure.

Q.

What is Ultrasound? Explain the applications of ultrasound. [5 MARKS]

Q.

A steel tube of length $1m$ is struck at one end. A person with his ear close to the other end hears the sound of the blow twice, one travelling through the body of the tube and the other through the air in the tube. Find the time gap between the two hearings. Use the table in the text for speeds of sounds in various substances.

Q. Short note on echo.

Q.

Explain how do bats locate the obstacles and prey in their way.

Q.

For a sound wave, the reflected wave, incident wave and the normal to the reflecting surface always lie ___.

1. in different planes

2. in the same plane

3. in planes perpendicular to each other

4. incident and reflected waves are in the same plane while normal is in a perpendicular plane

Q.

How is ultrasound used for cleaning?

Q. Question 12
A girl is sitting in the middle of a park of dimension $12m\times 12m$. On the left side of it there is a building adjoining the park and on right side of the park, there is a road adjoining the park. A sound is produced on the road by a cracker. Is it possible for the girl to hear the echo of this sound? Explain your answer.

Q.

Name the instrument that is used for listening to sounds produced within the body.

Q. 1) Explain how defecrs in a metal block can be detected usngu ultra sound

Q. The defects in metal blocks are generally detected using

1. Audible sound waves
2. Infrasonic sound waves
3. Ultrasonic sound waves
4. Supersonic sound waves

Q. Which of the following are characteristics of both sound and light waves?

1. Both travels with the same speed
2. Both can travel through vacuum
3. Both obeys laws of reflection
4. Both are forms of energy

Q.

What is the range of frequencies associated with:
ultrasonic sound?

Q. Uses of ultrasonic sound.

Q.

Explain how, bats use ultrasound to catch the prey.

Q.

Define multiple reflection of sound.

Q.

Does sound follow the laws of reflection as light does?

Q.

Name the device which is used to address a small gathering of people.

Q.

The direction in which the sound is incident and reflected makes equal angles with the normal to the reflecting surface, but the three are not in the same plane.

1. True

2. False