The Basics of Electricity: Part 3

The Basics of Electricity: Part 3

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.

• Resistance is measured in Ohms.

What influences Resistance?

• Material of wire: Aluminum & copper = low resistance

• Thickness of the wire: thicker wire = low resistance

• Length of wire: shorter wire = low resistance

• Temperature: lower temperature = low resistance

Multiple Choice

Resistance is the ________ to the flow of electrical current.

• redirection

• opposition

• change

• movement

Multiple Select

Resistance is influenced by...

• Material of wire

• Thickness of material

• Length of wire

• Temperature

Voltage

• The measure (“push”) 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.

• Volatage is measured in volts.

Multiple Choice

Voltage is the push that causes electrical currents to flow.

• True

• False

Electromagnets

• Electromagnets are made from a

  current-bearing coil of wire

  wrapped around an iron or steel

  core.

• The more times the wire is wrapped

  around the iron core the stronger

  the electromagnet.

How It Works

The current passing through the coils of wire

magnetizes the iron nail.

More coils around the wire

equals stronger magnetic field.

Multiple Select

Electromagnets can be made with which 3 components?

• A battery

• Wire

• A nail

• A plastic cup

Generators

• A generator is a machine that

  changes mechanical energy to

  electrical energy

• Usually use moving magnets to

  create currents in coils of wire.

Multiple Choice

A generator is a machine that

changes mechanical energy to

electrical energy

• True

• False

Motors

• A motor is a device that changes

  electrical or chemical energy to

  mechanical energy.

Electricity & Magnetism

• Electricity and magnetism are closely

  related.

• Both are caused by negative and positive

  charges in matter.

• Electricity can produce magnetism and

  magnetism can create electricity

  (electromagnets)