Two coherent monochromatic point sources $S_{1}$ and $S_{2}$ are placed in front of an infinite screen as shown in figure. Wavelength of the light emitted by both the sources is $λ .$ Initial phase difference between the source is zero.

Initially $S_{1} S_{2} = 2.5 λ$ and the number of bright circular rings on the screen is $n_{1}$ . If the
distance $S_{1} S_{2}$ is increased and made $5.7 λ$ the number of bright circular rings becomes $n_{2}$ .
The difference $n_{2} - n_{1}$ is:

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

answer is 3.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

For $S_{1} S_{2} = 2.5 λ$ max path different = $2.5 λ$
Min path different =0
Between $2.5 λ$ and 0 lie $2 λ$ and $λ \Rightarrow$ two circular bright fringes
$n_{1} = 2$
For $S_{1} S_{2} = 5.7 λ$ max path different = $5.7 λ$
Min path different =0
Between $5.7 λ$ and 0 lie $5 λ, 4 λ, 3 λ, 2 λ, λ \Rightarrow$ Five circular bright fringes
$\Rightarrow n_{2} = 5$