Question

During superposition of two waves of nearly equal frequencies, beats frequency is defined as the

• A. Sum of frequencies of interfering waves
• B. Number of times the resultant intensity becomes maximum or minimum in one second
• C. Average of frequencies of interfering waves
• D. Number of times the resultant amplitude becomes maximum or minimum in one second

Answer 1

Answer: (B)

Beats is the difference in the frequencies of two superimposing waves. Beats are noticed when the resultant wave acquire its higher amplitudes, due to both waves, sounding higher than the regular sound. The beats would occur $f_{1}-f_{2}=\Delta f$ times per second.