LESSON 2 - INDUCED CHARGES AND COULOMB'S LAW

Neutral atom

it has an equal number of protons (p⁺) and electrons (e⁻).

Equation: p+ = e−

This means the number of positively charged protons is equal to the number of negatively charged electrons.

Negatively charged

Atoms gained electrons

Positively charged

Atoms loses electrons

Charging by Friction

Two different materials are rubbed together.

Electron affinity

measure of the attraction of an atom to an electron.

Materials with higher electron affinity

capable of gaining electrons from those of lower electron affinity.

Triboelectric series

Arranged in order of increasing electron affinity from top to bottom.

One that is higher on list will become positively charged.

Charged by Conduction

Requires physical contact between charging body and neutral body.

when charged by negatively charged body

Neutral body becomes negatively charged

when charged by positively charged body

Neutral body becomes positively charged

Charged by Induction

Body may be charged without physical contact with charged body

Polarization

Happens when negative charges on neutral body are attracted toward charging body if latter is positive.

Conservation of Charge

Charges can neither be created nor destroyed, it only transferred from one body to another.

Coulomb

Discovered magnitude of electrical force between two charged particles.

Coulomb’s Law

Electrical force is directly proportional to products of magnitudes of charges and inversely proportional to square of distance between them.

Fe

electrical force

q1

charge 1

q2

charge 2

r

distance in meters

k - coulomb’s constant

9.0 × 10^9 N x m²/c²

𝟏. 𝟔𝟎𝟐 𝒙 𝟏𝟎−𝟏𝟗𝑪

charge of a single electron

Number of electrons=Total charge (Q) divided by charge of a single electron (e)

Formula used to find how many electrons were transferred.