Electric Charge

“Charge” is a property of subatomic particles.
Facts about charge:

■ There are basically 2 types: positive (protons)

and negative (electrons)

■ LIKE charges REPEL and OPPOSITE

charges ATTRACT

■ Charges are symbolic of fluids in that they

can be in 2 states, STATIC or DYNAMIC.

Items on the top more likely to give electrons to those below

​

​Triboelectric Series

Electric Charge – The specifics

Some important

constants:

•The symbol for CHARGE is “q”
•The unit is the COULOMB(C),
named after Charles Coulomb
•If we are talking about a SINGLE
charged particle such as 1 electron
or 1 proton we are referring to an
ELEMENTARY charge and often
use, e , to symbolize this.

Particle

Charge

Mass

Proton

1.6x10-19 C

1.67 x10-27 kg

Electron

1.6x10-19 C

9.11 x10-31 kg

Neutron

0

1.67 x10-27 kg

Charge is “CONSERVED”

Charge cannot be

created or destroyed
only transferred from
one object to another.
Even though these 2
charges attract initially,
they repel after
touching. Notice the
NET charge stays the
same.

Conductors and Insulators

The movement of charge is limited by the substance

the charge is trying to pass through. There are
generally 2 types of substances.

Conductors: Allow charge to move readily though it.
Insulators: Restrict the movement of the charge

Conductor = Copper Wire
Insulator = Plastic sheath

Charging and Discharging

There are basically 2 ways

you can charge
something.

1.Charge by friction

2.Induction

Induction and Grounding
The second way to charge something is via

INDUCTION, which requires NO PHYSICAL
CONTACT.

Induction/Noncontact: Electrophorus

Electric Field Springboard

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Gravity

We have called this ratio gravitational acceleration.

AND we have called it gravitational field.

On earth it's 9.8 (roughly 10) and can be measured in m/s² or N/kg.

Either way it is symbolized by g.

Electric Field

While the force is greater on the larger charge, the force/charge is the same.

This is called Electric Field


Follows direction of positive "test" charge

Electric Field Lines Examples

​Positive Point Charge

​Negative Point Charge

Attractive Forces

Repulsion Forces

Fields: Invisible/Non-contact Forces

Electrostatic

Gravity

Fg vs Fe