Answer:
a

b

Explanation:
From the question we are told that
The wavelength is 
The number of antinodal planes of the electric field considered is n = 5
The width is mathematically represented as



Generally the frequency the errors was made is mathematically represented as

Here c is the speed of light with value 
is the wavelength of the microwave has to be in order for there still to be five antinodal planes of the electric field along the width of the oven, which is mathematically represented as


So


Answer:
A
Explanation:
Snell's law states:
n₁ sin θ₁ = n₂ sin θ₂
where n is the index of refraction and θ is the angle of incidence (relative to the normal).
The index of refraction of air is approximately 1. So:
1 sin 30° = 1.52 sin θ
θ ≈ 19°
Answer:
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