Question

A parallel beam of white light is incident normally on a diffraction grating. It noted that the second order and third order spectra partially overlap. Which wavelength in the third-order spectrum appears at the same angle as the wavelength of 600nm in the second order spectrum?Options a. 300m b. 400m c. 600 m d. 900m​

Answer 1

Answer:

option b.400m

Explanation:

if liked follow

Answer 2

Answer:

400nm

Explanation:

the option should be in nm.

for me

wavelength is represented as π

and angle is @

as we know

mπ = dsin@

so for second spectra

(2)(π)=dsin@

for third spectra :

(3)π`=dsin@

by dividing

(3)π` / (2)π = dsin@ / dsin@

[dsin@=dsin@ as given]

(3)π` = (2)π

[π = 600nm]

π` = (600)(2) / (3)

π` = (200)(2) = 400nm