Question

Two speakers C & D are driven in step at 600 Hz by the same audio oscillator. these speakers both start out at 5.0 m from the listener, but speaker C is slowly moved away. if C keeps moving, at what distance d will the speakers produce the second destructive interference at the listener? the speed of sound is 340 m/s.
A) 0.97 m

B) 0.86 m

C) 0.45 m

D) 0.28 m

Answer 1

Answer:

option B

Explanation:

given,

frequency of the speaker = 600 Hz

speed of sound = 340 m/s

wavelength = ?

$\lambda = \dfrac{v}{f}$

$\lambda = \dfrac{340}{600}$

$\lambda = 0.567 m$

for second destructive interference,

the path difference,

$d =(2k-1)\dfrac{\lambda}{2}$

k = 2

$d =(2\times 2-1)\dfrac{\lambda}{2}$

$d =\dfrac{3\lambda}{2}$

$d =\dfrac{3\times 0.567}{2}$

d = 0.86 m

the correct answer is option B