Transcript test_review_magnetism

WHOLE BRAIN
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household
120 V to the 8 V required by the
doorbell. If the Primary Coil on the
transformer has 150 turns, how many
turns are present on the Secondary
Coil?
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household
120 V to the 8 V required by the
doorbell. If the Primary Coil on the
transformer has 150 turns, how many
turns are present on the Secondary
Coil?
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household
120 V to the 8 V required by the
doorbell. If the Primary Coil on the
transformer has 150 turns, how many
turns are present on the Secondary
Coil? STEP DOWN TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is used
to convert standard household 120 V to the 8
V required by the doorbell. If the Primary Coil
on the transformer has 150 turns, how many
turns are present on the Secondary Coil? STEP
DOWN TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•Electric doorbells found in many homes
require 8 V to operate. A transformer is
used to convert standard household 120 V
to the 8 V required by the doorbell. If the
Primary Coil on the transformer has 150
turns, how many turns are present on the
Secondary Coil? STEP DOWN
TRANSFORMER
WHOLE BRAIN
•-- Now turn to your partner and tell them
how you go about solving them
---First you write the?
---Then you look for
---Then you…..
WHOLE BRAIN
•If the voltage in the above
transformer has gone up, what
happens to the current in the
transformer?
WHOLE BRAIN
•If the voltage in the above
transformer has gone up, what
happens to the current in the
transformer?
•If one went up….the other MUST GO
DOWN (The numbers have a
relationship I = V/R)
WHOLE BRAIN
•If the primary coil of wire on a transformer
is kept the same and the number of turns
of wire on the secondary is increased, how
will this affect the voltage observed at the
secondary?
WHOLE BRAIN
•If the primary coil of wire on a transformer
is kept the same and the number of turns
of wire on the secondary is increased, how
will this affect the voltage observed at the
secondary?
More wires are wrapped on the
secondary coil….so voltage is stepped up
Warm-UP
•Which of the following uses an
electromagnet to convert electrical energy
to another form?
Warm-UP
•Which of the following uses an
electromagnet to convert electrical energy
to another form?
•YOUR SPEAKERS
Whole Brain
•The property of matter that is
responsible for both electricity and
magnetism is:
Whole Brain
•The property of matter that is
responsible for both electricity and
magnetism is:
•CHARGE
Whole Brain
•What is this?
Whole Brain
•What is this?
•Electromagnet
WHOLE BRAIN
•-- Now turn to your partner and tell them
•---about an electromagnet
•---what your speakers use
•---the relationship of the numbers…when 1
goes up the other goes….
Whole Brain
•What happens if you increase the
current in an electromagnet?
Whole Brain
•What happens if you increase the
current in an electromagnet?
•The magnetic field will be stronger
WHOLE BRAIN
•Three ways you can increase the
strength of an electromagnet are:
WHOLE BRAIN
•Three ways you can increase the strength
of an electromagnet are:
•INCREASE CURRENT
•INCREASE NUMBER OF TURNS of wire
•Wrap the wire around an Iron CORE
Whole Brain
•Placing the north pole of a magnet
near the south pole of another
magnet results in:
Whole Brain
•Placing the north pole of a magnet
near the south pole of another
magnet results in:
•ATTRACTIVE FORCE
WHOLE BRAIN
Which shows a repulsive force?
WHOLE BRAIN
Which shows a repulsive force?
WHOLE BRAIN
•Which part of a bar magnet has
the strongest magnetic force?
WHOLE BRAIN
•Which part of a bar magnet has
the strongest magnetic force?
•BOTH POLES ARE EQUALLY STRONG
WHOLE BRAIN
WHOLE BRAIN
•The type of magnet made using
wires and electric current is a(n):
WHOLE BRAIN
•The type of magnet made using wires
and electric current is a(n):
•Electro magnet
electr = electricity
WHOLE BRAIN
•-- Now turn to your partner and tell them
•---attractive forces
•---repulsive forces
•--3 ways to increase the strength of the
electromagnet
WHOLE BRAIN
•A motor’s basic function is to
convert:
WHOLE BRAIN
•A motor’s basic function is to
convert:
WHOLE BRAIN
•A motor’s basic function is to convert:
•ELECTRICAL ENERGY into
MECHANICAL ENERGY
WHOLE BRAIN
•Electromagnetic induction occurs
when:
WHOLE BRAIN
•Electromagnetic induction occurs
when:
•current is induced in a wire by an
moving magnet.
WHOLE BRAIN
•A current can be induced to flow in a
coil when:
•Sliding magnet across a coil of wire
•NOT JUST HOLDING THE MAGNET
WHOLE BRAIN
•Mechanical energy is
transformed into electrical
energy by a(n):
WHOLE BRAIN
•Mechanical energy is
transformed into electrical
energy by a(n):
WHOLE BRAIN
•Mechanical energy is
transformed into electrical
energy by a(n):
• A GENERATOR
WHOLE BRAIN
•electric motor spins because:
WHOLE BRAIN
•electric motor spins because:
•an electromagnet attracts and
then repels magnets in the
rotor.
WHOLE BRAIN
•If a 12-inch long bar magnet is
cut into two pieces, one inch
from the north pole end of the
magnet:
WHOLE BRAIN
•If a 12-inch long bar magnet is
cut into two pieces, one inch
from the north pole end of the
magnet:
WHOLE BRAIN
•What happens if you reverse the direction
of current flow in an electromagnet?
WHOLE BRAIN
•If a 12-inch long bar magnet is cut
into two pieces, one inch from the
north pole end of the magnet:
•You make 2 magnets (both have a
north and a South pole)
WHOLE BRAIN
•What happens if you reverse the direction
of current flow in an electromagnet?
•The magnetic field reverses (poles are
switched)
WHOLE BRAIN
•-- Now turn to your partner and tell them
•---What a motor does……
•--what a generator does
•---How current can be induced / not induced
•--What happens when you cut a magnet in
half