Lesson 1 Ohm's Law

Electric Current

• Amount of charge passing through any point in a conductor per unit time.

• the movement of tiny charged particles (electrons) through a wire, making devices like bulbs and fans work.

Conventional current

• It assumes that positive charges flow from the positive terminal of a battery to the negative terminal.

• This is the traditional way scientists originally defined current, before they knew electrons were the actual charge carriers.

Electron Current (I)

• electrons (which are negatively charged) move in the opposite direction—from the negative terminal of the battery to the positive terminal.

• This is what actually happens in a circuit.

Direct current

current that travels in one direction

Alternating current

a charge that changes direction at a regular interval

Resistance (Ω)

Opposition of a material to the flow of electric current.

Resistors

Regulate the amount of current passing through a conductor. Values may be fixed or variable.

Fixed Resistors

has a resistance value that cannot be changed or adjusted.

Variable Resistor

it allows the resistance value to be adjusted manually.

Circuit Diagram

• Represent the electrical circuit using industry- standard symbols.

• It shows the path of the electrical energy flow, and how the components are connected.

pictorial style and schematic style

two types of circuit diagrams

pictorial style

type of circuit diagram that uses simpler illustrations of the components
so that it would be more understandable to a less technical audience.

schematic style

type of circuit diagram that uses industry-standard symbols