Sec. 4 Electrical Circuits
Sec. 4 Electrical Circuits
Ohm’s Law
• Resistance= Voltage (volts)
(ohms) Current (amps)
R=V V=C X R
C
Ohm’s Law• Resistance= Voltage (volts)
(ohms) Current (amps)
Resistance= 10 ohms
Voltage= 20 volts
Current= ?
10= 20
C
Current = 2 amps
Ohm’s Law• Resistance= Voltage (volts)
(ohms) Current (amps)
Resistance= ?
Voltage= 60 volts
Current= 2 amps
Find the missing variable.
Resistance Voltage Current
75 volts 25 amps
100 volts 2 amps
2 ohms 80 volts
4 ohms 120 volts
• Resistance= Voltage (volts)
(ohms) Current (amps)
measured with unit
voltage voltmeter Volt
current ammeter amp
resistance multimeter Ohm
basic features of a circuit:
1. source of electrical energyeg. battery
2. have device run by electrical energyeg. light bulb
3. connected by conducting wires & switch= used to open & close circuit
closed- circuit complete open- circuit broken
Electrical Flow [02:04]
resistor• uses electrical energy as it interferes w/ flow of charge
Series and Parallel Circuits [00:36] .
2 types of circuits: series & parallel
seriescircuit
only 1 path
for current to take
advantage disadvantages
simple to build
if 1 light goes out-
all go out
more bulbs added-
greater resistance
series series circuitcircuit
Christmas tree lights
series series circuitcircuit
several pathsfor current
to takeadvantage
more branches added-
decreased resistance
if 1 light goes out-
other stay lit
household household circuits-circuits-parallel parallel circuitscircuits
series circuits vs. parallel circuits
comparing circuits slideshow
Series and Parallel Circuits [02:02]