circuits and magnets

1. Electricity & Magnetism

2. +
-
+
+
++
The world is filled with electrical
charges:
+
+
+
+
+
-
-
- -
-
-
- --

3. What is this electrical potential
called?
Static Electricity
- -
-
-
-
-
- +
++
+
+

4. Static Electricity
The build up of an electric charge
on the surface of an object.
The charge builds up but does not
flow.
Static electricity is potential
energy. It does not move. It is
stored.

5. Electricity that moves…
Current: The flow of electrons
from one place to another.
Measured in amperes (amps)
Kinetic energy

6. How can we control currents?
With circuits.
Circuit: is a path for the flow of
electrons. We use wires.

7. There are 2 types of currents:
Direct Current (DC) – Where
electrons flow in the same
direction in a wire.

8. There are 2 types of currents:
Alternating Current (AC) –
electrons flow in different
directions in a wire

9. There are 2 types of circuits:
Series Circuit: the components
are lined up along one path. If
the circuit is broken, all
components turn off.

10. Series Circuit

11. There are 2 types of circuits:
Parallel Circuit – there are several
branching paths to the
components. If the circuit is
broken at any one branch, only
the components on that branch
will turn off.

12. Parallel Circuit

13. What is Resistance?
The opposition to the flow of an
electric current, producing heat.
The greater the resistance, the
less current gets through.
Good conductors have low
resistance.
Measured in ohms.

14. What is Voltage?
The measure of energy given to
the charge flowing in a circuit.
The greater the voltage, the
greater the force or “pressure”
that drives the charge through the
circuit.

15. Ohm’s Law
Resistance = Voltage / Current
Ohms = Volts / Amps

16. Practice with Ohm’s Law
Ohms Volts Amps
4 100 25
15 150 10
2 30 15

17. Magnets
•Like Charges
Repel
•Opposite
Charges Attract

18. What is an electromagnet?
Electromagnet – a magnet made
from a current bearing coil of wire
wrapped around an iron or steel
core.

19. What is a generator?
Generator – a machine that
changes mechanical energy to
electrical energy
Usually use moving magnets to
create currents in coils of wire.

20. What is a motor?
Motor – a device that changes
electrical energy to mechanical
energy that can do work.

21. That’s It !!!!