Question

A transparent film of thickness 250 nm and index of refraction of 1.40 is surrounded by air. What wavelength in a beam of white light at near-normal incidence to the film undergoes destructive interference when reflected?

a. 400 nm
b. 500 nm
c. 550 nm
d. 600 nm

Answer 1

The wavelength in a beam of white light at near-normal incidence to the film that undergoes destructive interference when reflected is 700 nm.

Step-by-step explanation:

To find the wavelength in a beam of white light at near-normal incidence to the film that undergoes destructive interference when reflected, we can use the formula:

wavelength = 2 * thickness * index of refraction

Plugging in the given values, we get:
wavelength = 2 * 250 nm * 1.40 = 700 nm

Therefore, the wavelength that undergoes destructive interference when reflected is 700 nm.

The wavelength in a beam of white light at near-normal incidence to the film that undergoes destructive interference when reflected is 700 nm.