Question

The professor then adjusts the apparatus. The frequency that you hear does not change, but the loudness decreases. Now all of your fellow students can hear the tone. What did the professor do? (a) She turned off the oscillator. (b) She turned down the volume of the speakers. (c) She changed the phase relationship of the speakers. (d) She disconnected one speaker.

Short answer

The correct option is D

Step-by-step solution

Important Concepts

The speed of sound is given by\[{v_s} = 340m/s\]

Reasoning

We know that the interference of the sound waves occurs when there are two, or more, sound sources. In this case, there are two sound sources and initially, some students hear a loud voice while other students hear nothing. This means that there is constructive interference on your place and there is destructive interference on the other students who hear nothing. The professor maintains the same frequency of the sound waves and the sound level decreases and all the students now are hearing but at low volume. This means that there are no interferences anymore which means that the professor disconnected, one of these two speakers.

Hence,The correct option is D