Current and CircuitsCurrent and Circuits

Power and control all rolled into Power and control all rolled into one fun filled adventure…not one fun filled adventure…not

really really

What Is A Current? What Is A Current? • CurrentCurrent: the rate at which : the rate at which

charges pass a given pointcharges pass a given point

Made by electrons moving in Made by electrons moving in a wirea wire

AC/DC...what does that AC/DC...what does that mean?mean?

• AC/DCAC/DC: explains how current gets : explains how current gets movedmoved

DCDC: Direct Current (one-direction): Direct Current (one-direction)

ACAC: Alternating Current (bi-directional): Alternating Current (bi-directional)

VoltageVoltage

• VoltageVoltage: the number : the number of electrons that are of electrons that are in an energy sourcein an energy source

Voltage can varyVoltage can vary

• Depends on Potential EnergyDepends on Potential Energy

ResistanceResistance• ResistanceResistance: opposition : opposition

to the flow of charge to the flow of charge

Expressed in ohms

ΏAs resistance increases…current decreases!!!!As resistance increases…current decreases!!!!

Ohm’s Law Ohm’s Law • Amperes (A) = Amperes (A) = voltsvolts (V) (V) ohms (Ώ)ohms (Ώ)

I = Current I = Current

V = VoltageV = Voltage

R = ResistanceR = Resistance

I = I = VV RR

Electric PowerElectric Power• The rate at which electrical energy is The rate at which electrical energy is

used to do workused to do work

Expressed in Watts (W)Expressed in Watts (W)

Power = voltage x currentPower = voltage x current

P = V x IP = V x I

CircuitsCircuits• Complete, closed path through which Complete, closed path through which

electric charges flowelectric charges flow

Closed Open

Two Types of CircuitsTwo Types of Circuits• 1. 1. SeriesSeries: all parts are connected in one loop: all parts are connected in one loop

Types Of CircuitsTypes Of Circuits

• 2. 2. ParallelParallel: different loads are : different loads are located on separate brancheslocated on separate branches