Question

1) How would you describe thunder and the light from lightening as waves?

-A) Thunder longitudinal, lightening transverse

-B) Thunder transverse, lightening transverse

-C) Thunder transverse, lightening longitudinal

-D) Thunder longitudinal, lightening longitudinal

2) Suppose the longitudinal component of a wave created by an earthquake is travelling from east to west. As it passes through your position, how would you expect to move?

-A) Both up and down, and north and south

-B) east and west

-C) north and south

-D) up and down

3)What is the distance between the center of a condensation and the center of an adjacent rarefaction in a sound wave of wavelength λ?

-A)  2λ

-B)  λ/4

-C)    λ

-D)  λ/2

4) A certain dog whistle simultaneously emits a range of frequencies above 50 kHz. How can this sound be characterized?

-A)  Infrasonic

-B) Ultrasonic

-C)  Pure Tone

-D) None of the above

Answer 1

(1)Consider thunder as a sound wave and lightning as a light wave. As sound wave is longitudinal and light wave is transverse so- option(A) is correct. (2)Since vibration of paticles in a longitudinal wave is to and fro about mean position in the same direction of wave propagation. So as earthquake waves are travelling from east to west so we are expect to move along east and west direction. Option (B) is correct. (3)Distance between centre of condensation and rarefaction is equal to half of the wavelenth. So option (D) is correct. (4)The frequencies above 20KHz are called ultrasonic waves.It can not be called pure note because it is not a single frequency wave but it is a range of frequencies. So option (B) is correct.