Electricity and Magnetism

Voltage (V) is the pressure that makes electricity move.

1. Electricity can be thought of as water.

a. The higher the water tank, the more water pressure

b. The thicker the pipes, the more water can move through.

c. The more resistance to water flow, the less will move

d. Hoses must be connected to circulate water

e. Water must be pumped to move

Batteries are the “pump” that makes electricity move.

1. Batteries do not “make” electricity, they release it from chemical bonds

2. Batteries do not “store” electricity, they release it from chemical bonds

3. Batteries come in two flavors

a. Dry cell ~ like flashlight batteries. They are dry inside.

b. Wet cell ~ like car batteries. They have strong, very strong acid inside.

Three things have to be known about electricity, to make much sense of it.

Resistance ~ the frictional forces slowing the movement of electricity. It is shown as “Ω”, and is an ohm, or “R”.

Voltage difference ~ how much pressure is in a line. It is shown as “V”, or “V”.

Current ~ how much electricity actually gets through, it is shown as “A” or “I”.

Ohm’s law says that

Voltage Difference

Amps = --------------------------------------

Resistance

So... How much current will get through a circuit with

2 Ω of resistance and 24 V of electrical pressure?

Ohm’s law says that

Voltage Difference

Amps = --------------------------------------

Resistance

So... How much current will get through a circuit with

2 Ω of resistance and 24 V of electrical pressure?

24 V ÷ 2Ω = 12 amps.

Magnetism

1. Closely related to electricity, in fact one of the 4 forces of nature is the electromagnetic force.

Magnetism

1. Closely related to electricity, in fact one of the 4 forces of nature is the electromagnetic force.

2. Magnetism moves by force “fields”

a. There is no particle of magnetism, like an electron with electricity.

Magnetism

1. Closely related to electricity, in fact one of the 4 forces of nature is the electromagnetic force.

2. Magnetism moves by force “fields”

a. There is no particle of magnetism, like an electron with electricity.

b. There are always two poles, always.

I. North and South

II. Cannot be separated

Magnets come in two types.

1. Electromagnets

2. Permanent magnets

Magnets come in two types.

1. Electromagnets

2. Permanent magnets

Permanent magnets

have “domains” that

line up north to south,

and amplify the

magnetic effect.

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