Question

I dont understand thin film interference. Thanks in advance

n-1.00 n-1.33 n=1 50 3. A thin film of thickness t and index of refraction 1.33 coats a glass with index of refraction 1.50 as shown above. Which of the following thicknesses t will not reflect light with wavelength 640 nm in air? (A) 160 nm (8) 240 nm (C) 360 nm (D) 480 nm 4. Lenses in fine quality cameras are coated to reduce the reflection from the lenses. If the coating material has an index of refraction between that of air and glass, what thickness of coating will produce the least reflection? (A) one-quarter of the wavelength in the coating (B) one-third of the wavelength in the coating (C) one-half of the wavelength in the coating (D) one wavelength in the coating mcident light ncident light ncident light eye Light strikes three different thin films, which are in air, as shown above. If t denotes the film thickness and λ denotes the wavelength of the light in the film, which films will produce constructive interference as seen by the observer? (A) I only (B) II only (C) III only (D) Il and IIl only 5.

Answer 1

In the interference due to films such as soap films in air or coating a film over glass, we can have two 2 cases. So let us understand the concept first

Dij DATE PAGE Cases to me diu eusth 2

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PAÇE SoL ptoblemt ㄧㄧㄧㄚ EF35 this medium 3 wle ne MRAs n((,,h@f Na凤 +tavM m 1、51eM/m.n p.) 2. //2. 2八七 2X133 t こ 2- 120.5 nm 2