Question

If two tuning fork A and B are sounded together they produce 4 beats per second. A is then slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256. The frequency of B will be
A. 259
B. 252
C. 260
D. 262

Answer 1

Correct Answer - B
`n_(B) = n_(A) +- 4`
`= 256 +- 4 = 260 or 252 Hz`
`n_(B) = n_(A) +- 2`
`= 256 +- 2 = 258 or 254 Hz`
Before loading fequency increases by 2 for unknown loaded for k. When known is loaded its frequency decreases by 2
`n_(B) = 252 Hz`