Consider the following statements regarding the Doppler effect in sound waves: 1. The apparent frequency of sound increases when the source moves towards a stationary observer. 2. The apparent frequency of sound decreases when the observer moves away from a stationary source. Which of the statements given above is/are correct?

💡 Solution & Explanation

Both statements describe correct manifestations of the Doppler effect, where relative motion between a sound source and an observer compresses or stretches the sound wave front intervals, altering the perceived frequency. When a sound source approaches an observer, wave crests are crowded together, resulting in a higher pitch, whereas receding motion spaces them out, lowering the pitch. The Doppler shift formula incorporates the individual speeds of both the source and the observer relative to the propagation medium.