Question

In ydse how many maxima can be obtained on the screen of wavelength= 2000a strong and d= 7000a

Answer 1

Explanation:

Let y be wavelength, Ф be angular width of a fringe and d be distance between two slits.

Ф = y / d

Therefore maximum angle can be 90° hence number of fringes:

(n) = Sin 90° / Sin Ф

As Sin Ф is very small Sin Ф ≈ Ф

n = 1 / Ф

n = d / y

700 / 200 = 7/2

Number of maxima or minima = 2n + 1

2 × 7/2 + 1 = 8

The answer is thus : 8