Question

What formula gives the strength of an electric field, E, at a distance from a known source charge?

Answer 1

Hello!

The answer is: Coulomb's law equation.

Why?

The Coulomb's law states that the strength of an electric field (between two charges) can be calculated by multiplying their charges and dividing it into the square of the distance between their centers.

$E=\frac{k*q*Q}{d^{2} }$

Where:

E = Electric Field Strenght

$k=9.0*10^{9} \frac{N.m^{2} }{C^{2} }$

$q=TestCharge\\Q=SourceCharge$

d = separation between charges (m)

Have a nice day!

Answer 2

Explanation:

The electric field is defined as the ratio of electric field per unit test charge. Mathematically, it can be written as :

$E=\dfrac{F}{q}$

F is the electrostatic force i.e.

$F=k\dfrac{Qq}{r^2}$

$E=k\dfrac{Q}{r^2}$...........(1)

Where

r is the distance from the one charge to test charge

Q is the source charge

k is electrostatic constant, k = 9 × 10⁹ N-m²/C²

Hence, the electric field strength at a distance r is given by equation (1)