Question

1. In a particular double-slit experiment, the distance between the slits is 50 times the wavelength of the light. Find the angle (in degrees) at which the first-order maximum occurs.

1. 2.78
2. 1.15
3. 5.60
4. 0.01

Answer 1

For nth maxima,

dsin end

Given ,

$d = 50\lambda$

And for first order maxima, n = 1

Therefore,

$(50\lambda)\sin\theta=\lambda$

$\sin\theta=\frac {\lambda}{ 50\lambda}$

$\ \theta=sin^{-1}\frac {1}{ 50}$

$\boxed {\ \theta=1.15\degree}$

Therefore, the correct option is (b).