📋 Formulario

Complete Theory

Worked Examples

Example 1Field and potential of a charged sphere
Example 2Parallel-plate capacitor with a dielectric

Exercises with Solutions

Exercise 1Coulomb's lawMedium
📋 Problem to solve
Two point charges q1=+3μCq_1 = +3\,\mu\mathrm{C} and q2=2μCq_2 = -2\,\mu\mathrm{C} are placed in vacuum at a distance r=0.3mr = 0.3\,\mathrm{m}. Compute: (a) the electrostatic force between them; (b) the electric field produced by q1q_1 at the location of q2q_2.
📌 Given data
q_1=3\times10^{-6}\,Cq_2=-2\times10^{-6}\,Cr=0.3\,m
Exercise 2Gauss's lawHard
📋 Problem to solve
A non-conducting sphere of radius R=0.05mR = 0.05\,\mathrm{m} has a uniform volume charge density ρ=105C/m3\rho = 10^{-5}\,\mathrm{C/m^3}. Determine the electric field at distance r1=0.03mr_1 = 0.03\,\mathrm{m} from the centre (inside) and at r2=0.10mr_2 = 0.10\,\mathrm{m} (outside).
📌 Given data
R=0.05\,m\rho=10^{-5}\,C/m^3
Exercise 3Electrostatic potential energyHard
📋 Problem to solve
Three identical charges q=2μCq = 2\,\mu\mathrm{C} are placed at the vertices of an equilateral triangle of side a=0.1ma = 0.1\,\mathrm{m}. Compute the total electrostatic potential energy of the system.
📌 Given data
q=2\times10^{-6}\,Ca=0.1\,m