Electricity

1
Electricity

• HS Physical Science

2
Electric Charge

• Electric force is caused by electric charge.
• Electric charge is a property of the bits of
  matter within atoms.
• Electric force can cause matter to repel or
  attract because there are two kinds of charge-
  positive and negative.

3
Law of electric charge

• Pieces of matter with the same kind of charge
  repel each other.
• Pieces of matter with different kinds of charge
  attract each other.

4


_
_
_

5
Static Electricity

• An electric charge on an object that causes the
  object to attract or repel other objects.

6
How does it work?

• When you rub something, it allows charged
  particles of matter to move from one object to
  another.
• The invisible bits of negatively charged matter
  that move between objects are ELECTRONS.

7
Charge Conservation

• When an object becomes charged, no new charge is
  created charge is simply moved around.
• THE LAW OF CONSERVATION OF CHARGE All electric
  events occur by rearranging or moving charge.

8
Electric Discharge

• Acquiring excess charges is as easy as walking
  across a carpet- and so is losing excess charge.
• A rapid transfer of electrons is known as an
  electric discharge.
• Lightning is an example of an electric discharge.

9
The unit to measure charge

• Called the coulomb.
• One coulomb is a very large amount of charge.
• A strong lightning bolt carries 10 to 20
  coulombs.
• The spark that jumps between your finger and a
  doorknob is about one-millionth of a coulomb of
  charge.

10
Electric Current

• Electric current is the movement of electric
  charge through matter
• You measure the size of an electric current as
  the amount of charge flowing through matter in a
  period of time.

11
AMPERE

• The unit used to measure current is the ampere
  (A)
• In everyday use, the ampere is often shortened to
  amp.
• One amp is about equal to the amount of current
  that moves through the bulb in a large table lamp.

12
Conductor

• A material that charges move through easily
• Examples are metals like copper, aluminum and
  gold

13
Insulator

• A material through which charges do not move
  easily
• Examples are glass, plastic and wood

14
Resistance

• The opposition a material offers to moving charge
• Resistance decreases the flow of electric charges
• The greater the resistance of an electric
  conductor, the harder it is for charges to move
  through the material.

15
Ohm

• The unit for electrical resistance

16
Current

• The movement of electric charge through matter

17
Voltage

• The amount of potential energy given to a charge
• Batteries have positions of high and low
  potential.
• The difference between the high and low
  potentials provides the electric energy that
  moves the charges.

18
Volt

• The unit used to measure voltage.
• The potential, or voltage, of a battery depends
  on the chemicals used in the battery and on how
  the chemicals are arranged inside the battery.