Answer:
d)symmetry
Explanation:
Here is the complete question
In deriving the axial electric field for the ring-shaped charge distribution and the electric field from a long line of charge, the component perpendicular to the resulting field is zero because of what physical property? Answer a)integration b)superposition c)only net charge is important d)symmetry e) positive and negative charges cancel
Solution
The perpendicular components of the resulting electric field is zero because of symmetry since the charge is evenly distributed around the ring or line of charge. At one point, there is an electric field dE due to a small charge element dq and a corresponding electric field dE' due to a small charge element dq' opposite to dq.
Since the charges are symmetrical about the center, the horizontal (or perpendicular) components of the electric fields would cancel out causing the horizontal component of the resulting electric field to be zero.
So, the perpendicular component of the resulting electric field is zero due to symmetry.