Transcript Science Ch. 18 notes - Mrs. Gann`s 6th grade class

Ch. 18 Electricity &
Magnetism
Lesson 1 – Electricity
On a cold, winter day, you walk
across a wool carpet & then touch
a metal doorknob. Predict what will
happen. Explain why. 10 pts.
You may feel a small shock because of
static electricity. Walking on a wool carpet
transfers electrons from the carpet to your
body. You acquire an overall negative
charge, which will attract positive charges
in the doorknob.
A circuit in which electrical current
flows along a single path
• Series circuit
What kind of circuit is
this? How does it work?
It is a parallel circuit. In a parallel
circuit, current can follow more
than one path. When a resistor
in one of the paths breaks,
current can still flow along the
other paths.
Parallel VS. Series – In Christmas
lights
What type of circuit should be used for this electrical
device? 10 pts.
It should be a parallel circuit because if one bulb broke,
the rest would remain on. Also the bulbs would shine
more brightly than if a series circuit were used.
How do power plants increase or
decrease the voltage of electricity?
10 pts.
Power plants use one kind of transformer to
increase voltage before sending currents
through power lines. At the other end,
currents pass through another type of
transformer that reduces the voltage.
Electric charges do not move
easily through a(n)
_______________________.
Why is it dangerous to have electric
appliances near you when you are
taking a bath? 10 pts.
Water is an excellent conductor of electricity.
If an electrical appliance was dropped into
the water, the electricity could travel from
the appliance to your body & electrocute
you.
A magnet is also a magnetic
______________ because it
has two poles.
This drawing
shows the region
around a magnet
called the
_____________
________
How could you create an
electromagnet? 5 pts.
Wrap insulated wire around an iron bar, &
send electricity through the wire. The bar
becomes a magnet.
What is shown in the picture?
Explain how it works.
It is an electromagnet.
Electricity from the
battery flows through the
coiled wire. The nail will
remain magnetic as long
as current flows through
the wire.
How does a AC electric motor
work? 10 pts.
An insulated wire is coiled around the
armature. When current moves through
the wire coil, the armature becomes an
electromagnet. Attraction & repulsion
between the armature’s poles and the
poles of the permanent magnet cause the
armature to rotate.
Name three types of data
storage systems that are based
on magnetic materials. 5 pts.
• Video & audio recordings
• Credit cards
• Computer hard drives
Definitions for test
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Electricity
Static electricity
Current electricity
Conductor
Electric generator
Electric motor