Reflection of Sound

Q.

State two applications of an echo.

Q. Which of the following animal(s) can hear ultrasonic sound?

1. dogs
2. cats
3. Turtles
4. bats

Q.

Explain how bats use ultrasound to catch prey?

Q. Which of the following is used in radar?

1. Ultrasonic waves
2. Radio waves
3. Infrasonic waves
4. Sound in the audible range

Q.

An echo returned in $3s$. What is the distance of the reflecting surface from the source, given that the speed of sound is $342m/s$?

Q.

To detect the obstacles in their path, bats produce :

(a) infrasonic waves (b) ultrasonic waves

(c) electromagnetic waves (d) radio waves.

Q.

What do you mean by reflection of sound ?

State one condition for the reflection of a sound wave.

Name a device in which reflection of sound wave is used.

Q.

A person standing between two vertical cliffs and 640m away from the nearest cliff shouted. He heard the first echo after 4 seconds and the second echo 3 seconds later. Calculate the distance between the cliffs.

1. 176 m

2. 1700 m

3. 1760 m

4. 1800 m

Q.

Write four uses of echo which includes its uses in Sonar and Radar

Q.

How do bats avoid obstacles in their way, when in flight ?

Q.

State the use of echo by a bat, dolphin and fisherman.

Q.

Which technique is used by bats for navigation and location of food?

1. SONAR
2. CRO
3. Echolocation
4. MIR

Q.

The technique that uses ultrasonic waves to measure the distance, direction and speed of underwater objects?

1. SONAR

2. RADAR

3. Ultrasonography

4. Electrocardiography

Q.

What is reverberation? How can it be reduced? [3 MARKS]

Q.

Which of the following make use of multiple reflections?

1. Stethoscope

2. Pendulum

3. Curved ceilings of concert halls

4. Vibrating tong

Q.

Ultrasound can be used for which of the following purpose/purposes?

1. Echocardiography

2. Ultrasonography

3. MRI Scan

4. Loudspeaker working

Q.

For sound waves, angle of reflection is equal to angle of incidence.

1. True

2. False

Q. If the angle of incidence of sound wave is 30 degrees, then the angle of reflection will be ____.

1. 45 degrees
2. 30 degrees
3. 60 degrees
4. 75 degrees

Q.

This phenomenon reverberation can be observed in:

1. Auditoriums

2. Cinema halls

3. Indoor stadiums

4. All of these

Q.

The angle of reflection is always ______ the angle of incidence.

1. equal to

2. depends on medium

3. less than

4. greater than

Q. If the angle of incidence of sound wave is ${30}^{\circ }$, what is the angle of reflection?

1. ${40}^{\circ }$
2. ${50}^{\circ }$
3. ${30}^{\circ }$
4. ${20}^{\circ }$

Q. Which of the following phenomenon helps in the propagation of waves through optic fibre cables?

1. Refraction
2. Reflection
3. Total Internal Reflection
4. Rarefraction

Q.

What frequency do whales communicate at ?

1. Infrasonic frequencies as low as 16 Hz

2. Ultrasonic frequencies as high as 45 kHz

3. In the audible range of the human ear

4. Both A and B

Q.

Suggest four steps that can be taken while construction buildings to avoid problems that may occur due to multiple reflection of sound

Q. Ultrasound scanning is more harmful than X-ray.

1. False
2. True

Q.

Write three uses of ultrasonic sounds.

Q. The branch of science that deals with ultrasound is known as ___ .

Q. For a sound wave, the angle of reflection is alwaysangle of incidence.

1. greater than
2. less than
3. equal to

Q. State true or false.
Bats produce high-pitched ultrasonic squeaks and are reflected by objects such as preys which returns back to the bat's ear and helps it to know the distance of the prey.

1. False
2. True

Q.

Propagation of sound waves follow the laws of reflection.

1. No

2. Yes

3. Depends on the medium

4. Depends on the source