Question

At a distance r1 from a point charge, the magnitude of the electric field created by the charge is 395 N/C. At a distance r2 from the charge, the field has a magnitude of 119 N/C. Find the ratio r2/r1.

Answer 1

r₂/r₁ = 1.82

Step-by-step explanation:

The electric field due to a point charge, has the following expression:

`E =(k*q)/(r^(2))`

For a distance r₁, the magnitude of the electric field is 395 N/C, so we can solve for r₁², as follows:

r₁² =
`(k*q)/(395 N/C) }` (1)

For a distance r2, the magnitude of the electric field is 119 N/C, so we can solve for r₂², as follows:

r₂² =
`(k*q)/(119 N/C) }`

We can find the quotient r₂/r₁, from (1) and (2):

r₂/r₁ =
`√(395/119)` = 1.82