7.Sound wave is an example of ? a. Longitudinal wave b. Electromagnetic wave C. Transverse wave

5. Radio waves travel at the speed of sound. TRUE FALSE

3. Doubling the intensity of sound: a. Doubles the sound level. b. Increases sound level by factor of 2. C. Increases sound level by 3 dB.

1) A biological sonar activity used by animals to locate and identify nearby objects by sending ultrasounds and "hearing" them reflected back from them. a. Resonance   b. Echolocation   c. Doppler effect   d. Reverberation   2) The listener observes an increase in the frequency of a sound whenever    a. he approaches the source of sound.   b. the source of sound approaches him.   c. both him and the source of sound approaches each other.   d. any or all of the above.

which wave can propagate even in vacuum? a. electromagnetic wave b. longitudinal wave c. mechanical wave d. transverse wave

9. Longitudinal mechanical waves can pass throughA. solids. B. liquids. C. gases. D. All of the above.

How deep is the wave base of a wave if the wavelength of the same wave is 30 meters?  A. 15 METERS B. 60 METERS C. 1.5 METERS D. 6 METERS

8. If the distance from the source is doubled, the sound intensity of a spherical wave is *   a. the same b. doubled c. halved d. quadrupled e. none of the above

190. As a gust of wind blows across a field of grain, a wave can be seen to move across the field as the tops of the plants sway back and forth. This wave is a: A. polarized wave. B. interference of waves. C. longitudinal wave. D. transverse wave.

5. A car horn emits a frequency of 500 Hz in 20 °C air, which has a speed of sound of 343 m/s. If the car is moving toward a stationary observer at 15 m/s, what is the frequency that is observed? Your answer