This is a PowerPoint on the basics of electricity and circuits. It will take you from how an electrical current is made to current flow and how open and closed circuits work.

1. Electricity
Unit 8 Notes (Continued)

2. V. Electric
Current
A.How electric current is made
1. Electric current is the
CONTINUOUS flow of ELECTRIC
CHARGES through a material
2. The AMOUNT of charge that
passes through a wire in a given
time is the RATE of electric
current.

3. V. Electric
Current
A. How electric current is made
(continued)
3. Unit for rate of current-
AMPERE (Amp, A)
4. ELECTRIC CURRENT- a
complete, unbroken path that
charges can flow through

4. 4. Electric Current
a. CLOSED circuit: CONTINUOUS path through
which current flows
b. OPEN circuit: DISCONTINUOUS path through
which current CANNOT flow
1. turning a switch OFF
2. Fuses/circuit breakers

5. V. Electric
Current
B. Current Flow: affected by the
energy of charges and the
physical properties of the
objects the charges flow
through.

6. V. Electric
Current
B. Current Flow:
1. Voltage: what makes
electric charges move
2. Volts (V): the unit of
voltage

7. V. Electric
Current
B. Current Flow: (continued)
3. Resistance: how difficult it is
for charges to flow through an
object.
a. The greater the
resistance, the less
current.
b. Ohms ( Ω ): unit
measure of resistance

8. 4 Factors
that
determine
Resistance
▪ 1. Length of wire (shorter is faster)
▪ 2. Diameter of wire (fatter is faster)
▪ 3. Material of wire (conductive)
▪ 4. Temperature (cooler is faster)

9. If more
than one
path…
…Electricity will take the
path of least resistance.
This is called a
SHORT CIRCUIT.

10. VI. Electric
Circuits
A. Ohm’s law: V= I R
Where:
V is voltage
I is current
R is resistance

11. B. Types of
circuits
1. SERIES circuits- ONE path for the current to take
a. All objects (ex- light bulbs) will GO OUT if
one
goes out
b. Objects (ex- light bulbs) become DIMMER

12. 2. PARALLEL circuits- different parts of the
circuit on separate branches
a. Several PATHS for current to take
b. Even if one object (ex- light bulb)
burns out, charges can move through
OTHER branches and stay lit

13. 2. PARALLEL circuits- different parts of the
circuit on separate branches
c. Adding branches DECREASES
resistance
d. Brightness of bulbs STAYS the SAME