Answer:
b
Explanation:
light does not need a medium
it is refracted
Light is made up of little packets of energy called photons.
electromagnetic waves
The answer to this question is C
Answer:
The value is 
Explanation:
From the question we are told that
The dielectric constant is k = 1.5
The area of each plate is 
The distance between the plates is 
The charge on the capacitor is 
Generally the electric field in a vacuum is mathematically represented as

Generally
is the voltage of the capacitor which is mathematically represented as

Here
is the capacitance of the capacitor in a vacuum which is mathematically represented as

Here
is a constant with value
=> 
=> 
So


So

=> 
The electric field when the dielectric slab is inserted is mathematically represented as

=> 
=> 
Generally the electric field between the plates is mathematically evaluated as

=> 
=> 
Generally the potential difference between the plates is

=> 
A is the correct answer :D
The amount of energy is ALWAYS conserved based on the law of conservation of energy. Therefore, the amount of energy will remain the same.