Question

The electric field at point P due to a point charge Q a distance R away has magnitude E. In order to double the magnitude of the field at P, you could:__________.
a. double the distance to 2.
b. double the charge to 2 and at the same time reduce the distance to /2.
c. reduce the distance to /2.
d. reduce the distance to /4.
e. double the charge to 2.

Answer 1

Answer:

Option E, double the charge to 2, is the right answer.

Explanation:

Given the electric field at point = P

The point charge = Q

Distance =R

Magnitude = E

Due to a certain charge, the magnitude of the electric field at a point is defined as:

$E = \frac{kQ}{r^2}$

Here, we can see that E is proportionate to Q and 1/r^2

Hence, double the charge to 2 and at the same time reduce the distance to /2 will half the E

Therefore, doubling the charge will doubling E

So the answer is (e) is correct.