AIIMS 2019 Physics Doppler Effect MCQ Question

When two sound sources produce beats, the beat frequency is equal to the absolute difference between their frequencies. In this case, the observer hears 3 beats/s, indicating that the frequency of source B (f_B) can be calculated as f_B = f_A ± 3 Hz, where f_A = 256 Hz. Thus, f_B could be either 259 Hz or 253 Hz. The speed of sound in air is approximately 343 m/s, and using the formula $v = f \lambda$ (where $\lambda$ is the wavelength), we find that the difference in frequency (3 Hz) corresponds to a speed difference of 1 m/s, making option A correct. Other options are incorrect as they suggest larger speed differences that do not align with the observed beat frequency.