Science Test – 19 April (Topic- Sound)

The  minimum distance to hear echo is ?
a. 16.6 m
b. 18 m
c. 19.9 m
d. 26.6 m

When we hear a sound, we can identify its source from
a. wave length of sound
b. the overtones present in the sound
c. the intensity of sound
d. the amplitude of sound

 Astronauts in space communicate with each other by radio links because
a. Sound waves travel slowly in space
b. sound waves can’t travel in space
c. sound waves travel fastly in space
d. sound waves have low frequency

 The intensity level of the rustling of leaves is
a. 25 dB
b. 0 dB
c. 10 dB
d. 100 dB

 The speed of sound in solids is
a. 10 times that in gas
b. 20 times that in gas
c. 5 times that in gas
d. 15 times that in gas

1 bel is equal to
a. 100 dB
b. 50dB
c. 10dB
d. 20dB

 SONAR is the abbreviation of
a. small navigation and random
b. sky navigation and ranging
c. sun nuclear ranging
d. sound navigation and ranging

 The speed of sound varies with
a. humidity
b. temperature
c. both humidity and temperature
d. none of the above

 Old people can not hear sounds even above
a. 5,000 Hz
b. 15,000 Hz
c. 10,000 Hz
d. 8,000 Hz

 The amplitude and loudness are
a. inversely related
b. directly related
c. not related at all
d. inversly proportional

 Echoes maybe heard more than once due to
a. multiple reflections
b. single time reflection
c. refraction
d. diffraction of waves

The sensation of sound persists in our brain for about
a. 0.001s
b. 0.2s
c. 0.1s
d. 10s

 To communicate with each other, Elephants use
a. low frequency sound waves
b. low frequency light waves
c. high frequency sound waves
d. low frequency heat waves

. The speed of sound in air is
a. 343ms-1
b. 343ms-2
c. 341ms-1
d. 250ms-1

 The velocity of sound in a gas deoends on
a. wavelength only
b. density & elasticity of gas
c. intensity only
d. amplitude & frequency