Question

P and Q are two wires whose fundamental frequencies are 256 Hz and 382 Hz respectively. How many beats in two seconds will be heard by the third harmonic of A and second harmonic of B?

• A. 4
• B. 8
• C. 16
• D. zero

Answer 1

Answer: (B)

8

Answer 2

Beat frequency

$3\upsilon_{1} - 2\upsilon_{2} = 3 \times 256 - 2 \times 382$

$= 768 - 764 = 4s^{- 1}$

Number of beats produced in 2 seconds

= 4 × 2 = 8