Answer:
The intensity of light passing from the third polarizer is 3Io/16.
Explanation:
The law of Malus is given by

Let the incident intensity of light is Io.
The intensity of light passing from the first polarizer is

The intensity of light passing from the second polarizer is

The intensity of light passing from the third polarizer is

Answer:
n = 1.42
Explanation:
The refractive index for a medium is given by the ratio of the speed of light in vacuum to the speed of light in a medium.

So, the refractive index of the medium is 1.42.
Answer:
T=1.384×10⁶seconds
Explanation:
Given data
p (Intensity)=1.30 kw/m²
E (Energy)=1.8×10⁹ J
A (Area)=1.00 m²
T (Time required)=?
Solution
E=PT ................eq(i)
where E is energy
P is radiation power
T is time
Radiating Power is given as
P=pA
Where p is intensity
A is Area
Put P=pA in eq(i) we get
E=pAT
T=E/pA

Yes because if not people wouldn't understand how did you calculate electric field strength.
There is no factor on your list of choices that has any effect.