At a distance D from a very long (essentially infinite) uniform line of charge, the electric field strength is 1000 N/C. At what distance from the line will the field strength to be 2000 N/C? a. D/√2.
b. √2D.
c. D/2.
d. 2D.
e. D/4.

The correct option is (a).

Explanation:

We know that, the E is inversely proportional to the distance as follows :

We can write it as follows :

Put all the values,

So, the correct option is (a).

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probably not if net force is zero