Question

In Young's double slit experiment, the number of maximas obtained on a screen (including the central maximum) on both sides of the central fringe if $\lambda =2000A^o$ and $d=7000A^o$ , are

• A. 7
• B. 18
• C. 4
• D. 12

Answer 1

The correct option is A 7

$dsin\theta =n\lambda$
$sin\theta =n\frac{2000}{7000}$
$=\frac{2n}{7}$
So, n can take values. $(0,\pm 1,\pm 2,\pm 3)$ to have $sin\theta$ between $-1to+1.$
So, seven maxima can be obtained