To demonstrate the phenomenon of beats we need
Two sources which emit radiation of nearly the same frequency
Two sources which emit radiation of exactly the same frequency
Two sources which emit radiation of exactly the same frequency and have a definite phase relationship
Two sources which emit radiation of exactly the same wavelength
As we learnt in
Beat Frequency -
module of
- wherein
Where are frequency of two wave differ slightly in value of frequency.
Phenomena of beat frequency can be observed when two source of sound emit frequency of nearly same wave.
Option 1)
Two sources which emit radiation of nearly the same frequency
This option is correct.
Option 2)
Two sources which emit radiation of exactly the same frequency
This option is incorrect.
Option 3)
Two sources which emit radiation of exactly the same frequency and have a definite phase relationship
This option is incorrect.
Option 4)
Two sources which emit radiation of exactly the same wavelength
This option is incorrect.