9 When tuning a guitar by comparing the frequency of a strin

9. When tuning a guitar, by comparing the frequency of a string that is struck against a standard sound source (of known frequency), what does the one adjusting the tension in the string listen to?

Solution

Its the beats generated that the person listen to. If the Freq of the sound source is f1 and the freq of string is f2 then the beats generated per second is 1/|f1-f2|. So in order to tune it perfectly, desired no of beats per second should be as high as possible. When this situation is achieved, then , f1 = f2 and the guiter is tuned.