Question

Two slits are illuminated by a 602 nm light. The angle between the zeroth-order bright band at the center of the screen and the fourth-order bright band is 17.4 ◦ . If the screen is 138 cm from the double-slit, how far apart is this bright?

Answer 1

y = 43.2 cm

Step-by-step explanation:

As we know by the formula of diffraction we have

`a sin\theta = N\lambda`

here we have

`\theta = 17.4`

N = 4

`\lambda = 602 nm`

now we have

`a sin(17.4) = 4(602* 10^(-9))`

`a = 8.05 * 10^(-6) m`

now the distance of screen is 138 cm

now we can say

`(y)/(L) = tan\theta`

`y = L tan(\theta)`

`y = 138 tan(17.4) = 43.2 cm`