Page 432
Which direction will the current move when the coil is moved up?
Clockwise
A current with charges that flow in one direction is called
Direct Current
What is a generator?
When I turn the crank of a wind-up cell phone charger, or generator, I turn an armature in a(n) _______________.
Magnetic field
What does a transformer do?
A transformer is a device that increases or decreases voltage.
Which direction will the current move when the coil moves down?
A constantly reversing current is called
What does a slip ring in a generator do?
The slip ring turns with the armature and transfer current to the brushes
This generates a(n) _____________ in the wire, which powers the phone.
current
Which coil has more loops in a step-down transformer?
The primary coil has more loops
Which direction will the current move when the magnet moves up?
Clockwise
Why do you think we use alternating current today?
Example: It is easy to change AC voltage.
What does an armature in a generator do?
The motion of the armature in the magnetic field induces a current
Fill in the FIRST BLANK ONLY:
If you connect the output wires of the charger to a battery, _____________ will flow through the armature, producing a __________.
current
Why do some appliances have step-down transformers built in?
The appliance operates at a voltage lower than 120 volts in home circuits.
Which direction will the current move when the magnet moves down?
Counterclockwise
What is one way to induce an electric current?
You can move a coil through a magnetic field.
What does the crank in a generator do?
The crank rotates the armature.
Fill in the SECOND BLANK ONLY:
If you connect the output wires of the charger to a battery, _____________ will flow through the armature, producing a __________.
magnetic field
What is the ratio that shows the correlation between voltage and coils?
voltage (primary) / voltage (secondary) = coils (primary) / coils (secondary)
Make a general statement that relates to the motion of the circuit (up or down) to the direction of the current (clockwise or counterclockwise).
When part of the circuit moves up, the current flows clockwise. When part of the circuit moves down, the current flows counterclockwise.
Give an example of an electronic appliance that runs on DC (direct current).
flashlight, cell phone, TV
What does the brush in a generator do?
When the brushes are connected to a circuit, the generator can be used as an energy source.
The permanent magnet in the charger will then cause the armature to _______.
turn
What does a transformer consist of?
two separate coils of insulated wire wrapped around an iron core.