Coulomb’s Law and Electrical Fields

Flashcards covering the fundamental concepts of electrostatics, including charging processes, units, Coulomb's Law, and electric field strength based on the lecture notes.

Positively charged object

An object that has lost electrons.

Negatively charged object

An object that has gained electrons.

Isolators

Materials that are charged by using friction and will keep their charge until they are discharged by grounding them; only these materials can hold static charge.

Conductors

Materials that can be charged by using induction.

Coulomb ($C$)

The standard unit of electric charge.

Law of Conservation of Charge

Charge cannot be created or destroyed; it can only be transferred from one object to another.

Elementary charge on an electron

$$e = -1,6 \times 10^{-19} \, C$$

Elementary charge on a proton

$$p = +1,6 \times 10^{-19} \, C$$

milliCoulomb ($mC$)

$$1 \, mC = 1 \times 10^{-3} \, C$$

microCoulomb ($\mu C$)

$$1 \, \mu C = 1 \times 10^{-6} \, C$$

nanoCoulomb ($nC$)

$$1 \, nC = 1 \times 10^{-9} \, C$$

picoCoulomb ($pC$)

$$1 \, pC = 1 \times 10^{-12} \, C$$

Electrostatic Forces

Forces that occur between charged objects where like charges repel each other and unlike charges attract.

Newton's Third Law in Electrostatics

The principle stating that if charge $q_1$ exerts a force on $q_2$, then $q_2$ exerts an equal but opposite force on $q_1$.

Coulomb’s Law

The law stating that the electrostatic force $F$ is directly proportional to the product of the two charges ($q_1 \times q_2$) and inversely proportional to the square of the distance between them ($r^2$): $F = k \frac{q_1 q_2}{r^2}$.

Coulomb’s constant ($k$)

A proportionality constant used in Coulomb's Law with a value of $9 \times 10^9 \, N \cdot m^2 \cdot C^{-2}$.

Electrical Field

A region of space surrounding a charged object where another charged object will experience a force.

Direction of the electrical field

The direction in which a positive test charge would move if placed at a specific point.

Uniform Electric Field

An electric field, such as that between two charged parallel plates, where the field has the same strength throughout the region.

Electric Field Strength ($E$)

The magnitude of the electrostatic force ($F$) per unit positive charge ($q$), expressed as $E = \frac{F}{q}$.

Radial Electric Field Strength formula

$E = k \frac{Q}{r^2}$, where $Q$ is the charge responsible for creating the electric field and $r$ is the distance from that charge.