A source emits sound with frequency 1000 Hz. A second source emitting sound simultaneously causes a 4 Hz intensity variation to appear. What are the possible frequencies of the second source?
A)0.004 Hz and 4000 Hz
B)250 Hz and 4000 Hz
C)996 Hz and 4000 Hz
D)0.004 Hz and 250 Hz
E)996 Hz and 1004 Hz

Question

Quizplus · Accepted Answer

The intensity variation or beat frequency is the absolute difference between the two frequencies. Given a beat frequency of 4 Hz, the second source could be either 996 Hz or 1004 Hz.

A Source Emits Sound with Frequency 1000 Hz