Light is incident perpendicularly on four transparent films of different thickness. The thickness of each film is given in the drawings in terms of the wavelength λfilm of the light within the film. The index of refraction of each film is 1.5, and each is surrounded by air. Which film(s) will appear bright due to constructive interference when viewed from the top surface, upon which the light is incident?

1/4 λ film

Explanation:

Let L = total path length then L = 2 t where t is film thickness

There will be a 180 deg phase change at the air-film interface but no

phase change at the film-air interface

L = n * wavelength / 2 where n = 1, 3, 5, 7 etc

(the total path L must be an odd number of 1/2 wavelengths)

Or t = n * wavelength / 4 (the film must be an odd number

of 1/4 wavelengths thick)

1/4 λ film satisfies this condition

Note: Find the missing diagram in the attachment section.

explanation:

earth's surface is mainly heated by the absorption of infrared radiation from the sun.

evaporation occurs because molecules in liquid water are warmed ( usually by the sun) and vibrate quicker, becoming less dense and rise.

condensation occurs because molecules in water vapor are cooled and therefore vibrate more slowly thus becoming more dense and eventually fall to earth.

lines of equal barometric pressure on a weather map are called: isobars : lines of equal temp on a weather map are called: isotherms.​

power out to power in less than 100%