Question

In Young's double-slit experiment, how many maximas can be obtained on a screen (including the central maximum) on both sides of the central fringe ($\lambda =200\mathring{A}$ and $d=700\mathring{A}$)?

• A. $12$
• B. $7$
• C. $18$
• D. $4$

Answer 1

Answer: (B)

$7$

$dsin\theta =n\lambda$
$sin\theta =n\frac{2000}{7000}$
maximum value of $n$ is $3$
hence number of maxima are $3+3+1=7$(1 is central maxima)
option $B$ is correct