Question

13. Suppose that the strength of the electric field about an isolated point charge has a certain value at a distance of 1 m. How will the electric field strength compare at a distance of 2 m from the point charge

Answer 1

Answer: E/4 ( one - fourth of it electric field)

Explanation:

The electric field of a point charge is given below as

E =kq/r²

E = electric field,

K = electric constant

q = magnitude of electric charge

r = distance between point charge and electric field.

It can be seen that only E and r are the only variable here and also, E is inversely proportional to r²

Which implies that

E = k/r² , k = E × r²

E1 ×(r1)² = E2 × (r2)²

Let E1 = E, r1 =1, r2 = 2 and E2 =?

Let us substitute the parameters

E × 1 = E2 × 2²

E × 1 = E2 × 4

E = E2 × 4

E2 = E/4

Which implies that the electric field at the second distance (r =4) is one fourth of the initial electric field.