Just like visible light, microwaves can both reflect and transmit through certain material.

Consider a slab of such a material. It is 0.2 meters thick and its index of refraction is 1.1. On either side of the slab is air (n=1).

Part A

Suppose there is air (index of refraction 1.0) on both sides of the slab. Microwaves are normally incident on the slab.

What are the largest two wavelengths of radiation (in air/vacuum) such that there is no net reflection from the slab? Show your work.

Part B

Consider now the slab is placed on top of another material with index of refraction 1.2. Microwaves are normally incident on the slab from air.

Now what are the largest two wavelengths of radiation (in air/vacuum) such that there is no net reflection from the slab? Show your work.