Question

If a yellow light with a wavelength of 540nm shines on a double slits cuts 0.01mm apart, determine what angle you should look away from central fringe to see the second order fringe?

Answer 1

Answer on Question #43672, Physics, Optics

If a yellow light with a wavelength of $540\mathrm{nm}$ shines on a double slits cuts $0.01\mathrm{mm}$ apart, determine what angle you should look away from central fringe to see the second order fringe?

Solution:

The condition for maximum (bright spot) is

$$d \sin \theta = m \lambda$$

where $m = 2$ is order of interference, $d = 0.01 \times 10^{-3} \, \text{m}$ .

Thus,

$$\sin \theta = \frac {m \lambda}{d} = \frac {2 \cdot 5 4 0 \cdot 1 0 ^ {- 9}}{0 . 0 1 \cdot 1 0 ^ {- 3}} = 0. 1 0 8$$ $$\theta = \sin^ {- 1} (0. 1 0 8) = 6. 2 {}^ {\circ}$$

Answer: $\theta = 6.2{}^{\circ}$