JEE Advanced Model Paper 12 with solutions for online practice

Frequency of horn directly heard by observer = (

υ+υ0

υ+υc

) f . Frequency of echo, = (

υ

υ−υc

)
∴ Frequency of echo of horn as heard by the observer = (

υ+υc

υ

) (

υ

υ−υc

) f = (

υ+υc

υ−υc

) f
frequency of beats, “n . Wavelength of sound reaching the hill. Wavelength of sound of horn directly reaching the observer