## Sound Chapter -Test Paper

12/16/2014 CBSE

SOUND QUESTIONS - 1
(Q)1. Fill in the blanks:

(a) The loudness of sound is proportional to the _________ of the amplitude of the vibration.

(b)The speed of sound __________as it moves from solid to gaseous state.

(c) In any medium the speed of sound __________ with increase in temperature.

(d) The distance between two consecutive compression or two consecutive rarefaction is called the ____.

(e) The change in the density or pressure from a maximum value to minimum and then back to the maximum is called an ___________.

(f) The number of periodic oscillations per unit time is called the ________ of the sound wave.

(g) Sound is produced due to ________of different objects.

(h). Sound travels as a _________ wave through a material medium.

(i) Sound travels as successive _________ and ___________ in the medium.

2.
Q. A person has a hearing range from 20 Hz to 20 kHz. What are the
typical wavelengths of sound waves in air corresponding to these two
frequencies? Take the speed of sound in air as 344 m/s.

3. Q. The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?

4. Q. Explain how bats use ultrasound to reach a prey.

5.
Q. A sonar device on a submarine sends out a signal and receives an
echo 5 s later. Calculate the speed of sound in water if the distance of
the object from sub-marine is 3,625 m.

6. Q. A sound wave
travels at a speed of 339 ms�1. If its wavelength is 1.5 cm, what is the
frequency of the wave? Will it be audible?

7. Q. A stone is
dropped from the top of a tower 500 m high into a pond of water at the
base of the tower. When is the splash heard at the top ? Given, g = 10
ms�2 and speed of sound = 340 m/s.

8. Q. Which type of waves is produced when a stone is dropped on the surface of water in a pond ?

9. Q. What kind of waves are produced when a spring is pulled in the downward direction and released?

10. Q. What is the nature of electromagnetic waves?

11 Q.Give three important characteristics of wave motion.

12.Q. Differentiate between a periodic wave and a pulse. [http://jsuniltutorial.weebly.com/]

13.Q. Explain how ultrasounds help to detect cracks and flaws in metal blocks.

14.Q. Define time period of sound wave. What is its SI unit? How is it related with frequency?

15. Q. Explain, how compression and rarefaction are produced in air near a source of sound.