A source `S` of sound wave of fixed frequency `N` and an observer `O` are located in air initially
Channel: Doubtnut
Date: 26/07/2020

A source `S` of sound wave of fixed frequency `N` and an observer `O` are located in air initially at the space points `A` and `B`, a fixed distance apart. State in which of the following cases, the observer will NOT see any Doppler effect and will receive the same frequency `N` as produced by the source.