Answer to Question #7212 in Electricity and Magnetism for siddharth kapoor

Question

negative point charge 10-8 coulomb is situated in air at the origin of a rectangular coordinate system. What is the electric field intensity at a point on the positive x direction 3 metres from the origin?

Answer 1

Let's provide some denominations:
q = - 10^(-8) coulomb - the charge of the point
r = 3m - distance from the point

The intensity of the electric field is

E = k*q/r² = 8.9877*(-10^(-8))/3² = 8.9877*10^(-8)/9 = 0.99863*10^(-8) N/coulomb.