Welcome to Ryan Ormrod Web Solutions. I develop websites that are accessible.

Steve4Physics has made some really wonderful videos on Youtube. I wanted to make some notes privately at first but I thought I might as well share them on my blog so that somebody else can see them (and to avoid losing them myself).

+ve = Positive Charge (Proton) 1.60×10-19C
-ve = Negative Charge (Electron) -1.60×10-19C

Material becomes charged by gaining or losing electrons.

Like charges repel one another, but unlike charges attract one another.

SI = Coulomb (C).

Elementary Charge (e) = 1.60×10-19C (proton’s)

Electron’s Charge = -1.60×10-19C

6.25 x 10^18 Protons per C

Symbol for the amount of charge is Q or q

Current is:

The movement (Flow) of charge.

Don’t use amperage, use current.

Charge carriers = Whatever particles are moving and causing the current.

Conventional current = Imaginary current. Flows from the positive to the negative
as if the charge carriers we positive.


An AMP is equivalent to saying how many Coulombs (C) per second.

The SI unit for current is an ampere (AMP)

1 AMP is 1 Coulomb (C) per second.

To measure a current we use an ammeter.

I’ve chosen one I found on Amazon, it’s the Multimeter, Crenova MS8233D Auto Ranging Digital Multimeter AC Voltage Detector Portable Electronic Measuring Tester

We use the symbol I for current. E.g I = 2.0 Amp