Comprehensive notes for Chapter 13 Electrostatics. Covers Electric Charge, Electrostatic Induction, Coulomb's Law, Electric Field, Potential, Capacitors, and Applications.
Definition: Charge is a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types: Positive and Negative.
In the presence of a charged body, an insulated conductor develops positive charge at one end and negative charge at the other end. This process is called electrostatic induction.
A sensitive instrument used to detect the presence and nature of electric charge. Consists of a brass rod with a brass disk at the top and two thin gold leaves at the bottom in a glass jar.
The force of attraction or repulsion between two point charges is directly proportional to the product of the magnitude of charges and inversely proportional to the square of the distance between them.
F = k \frac{q_1 q_2}{r^2}
Where $k = \frac{1}{4\pi\epsilon_o} \approx 9 \times 10^9 Nm^2C^{-2}$.
Electric Field: A region around a charge in which it exerts electrostatic force on another charge.
Electric Field Intensity (E): Force acting on a unit positive charge. $E = F/q$. SI Unit: $NC^{-1}$. Vector quantity.
Electric Potential (V): Work done in bringing a unit positive charge from infinity to a point in the electric field. $V = W/q$. SI Unit: Volt ($V$). $1 V = 1 J/C$.
Capacitor: device to store charge. Consists of two parallel plates separated by dielectric.
Capacitance (C): Ability to store charge. $Q = CV$. SI Unit: Farad ($F$).