[two waves] pass a point [every second]... The answer is in the question (B)
Answer:

Explanation:
Given that
For straight wire
Charge density= λ
For hollow metal cylinder
Charge density=2 λ
We know that electric filed for wire given as


Now the electric filed due to hollow metal cylinder


Now by considering the Gaussian surface r<R then only electric fild due to wire will present.So
At r<R

now you justhave to solve the last numbers because...Iam sooo Lazy right now
Ideally, if all the magnetic of one winding cuts the other winding, and there isn't any loss in the transformer core or the resistance of the wire, then the voltage across each winding is proportional to the number of turns in its coil.
If you apply 100 V to a winding of 50 turns, then a winding that yields 20 volts
must be wound with
(20/100) of 50 turns = 10 turns