Science Test – 19 April (Topic- Sound)

 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 air is
a. 343ms-1
b. 343ms-2
c. 341ms-1
d. 250ms-1

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

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

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

 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

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

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

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

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

 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

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

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

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