Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
16 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
An area of a magnet where the magnetic force appears to be the strongest.
|
What is a Magnetic Pole? (464)
|
Like poles repel each other while opposites attract. No matter how small the piece of magnet may be, it will always have a North & South Pole.
|
|
|
A region where a magnetic force can be detected.
|
What is a Magnetic Field? (465)
|
This will vary with strenth of magnet, as distance between magnets increase the force of magnetism decreases.
|
|
|
The first naturally occurring magnetic rocks.
|
What are Lodestones? (463)
|
These rocks came from Magnesia, Greece and were discovered 3000 yrs. ago.
|
|
|
A Lodestone is a _______ __________ because it is magnetic all the time.
|
What is a Permanent Magnet? (463)
|
Magnetite is the only type of ________ ______________ known to man.
|
|
|
Scientists classify materials as either
______ or ______ depending on how easily they are magnetized and how long they hold the property. |
What is Magnetically Hard or Soft?
|
Iron can be made magnetic by rubbing it repeatedly with a magnet in the same direction.
|
|
|
A long, wound coil of insulated wire.
|
What is a Solenoid? (469)
|
Christian Oersted first experimented with an early form of this device which creates stronger magnetic fields.
|
|
|
A strong, magnet created when an iron core is inserted into the center of a current-carrying solenoid.
|
What is an Electromagnet? (470)
|
Makes a stronger magnet than a solenoid alone with addition of an iron core & wounds of insulated wire.
|
|
|
A microscopic magnetic region composed of a group of atoms whose magnetic fields are aligned in a common direction.
|
What is a Domain? (471)
|
When exposed to a magnet by rubbing in the same direction, a piece of iron becomes a magnet by the alignment of these ____________.
|
|
|
A device that converts electrical energy to mechanical energy.
|
What is an Electric Motor? (472)
|
This device uses a commutator and brushes to make current change direction producing a magnetic field in a coil that interacts with the magnetic field of the surrounding magnet causing the coil to turn.
|
|
|
The production of a current in a conducting circuit by a change in the strength, position, or orientation of an external magnetic field.
|
What is Electromagnetic Induction? (474)
|
In 1831, Michael Faraday discovered that a current can be produced by pushing a magnet in and out of a coil of wire. He called this process _______ __________.
|
|
|
An electric current can be produced in a circuit by a changing magnetic field.
|
What is Faraday's Law? (474)
|
Appears to produce energy from nothing but in reality supports the law of conservation of energy.
|
|
|
A device that uses electromagnetic induction to convert mechanical energy to electrical energy.
|
What is a Generator? (476)
|
A device that produces the electrical energy you use at home.
|
|
|
An electric current that changes direction at regular intervals; also called AC.
|
What is Alternating Current? (476)
|
A coil rotating in the magnetic field of a magnet creates this current that you use in the home.
|
|
|
A device that can change one alternating-current in the primary circuit to induce an alternating current in the secondary circuit.
|
What is a Transformer? (473)
|
Determines amount of voltage induced in the secondary coil by the number of loops or turns of wire in the coil. It can be increased or decreased by adding/removing coils.
|
|
|
A device that produces 50% greater voltage across the secondary coil than the voltage across the primary coil.
|
What is a Step-Up Transformer? (480)
|
Device used at or near a power plant to increase voltage of current to about 120,000 V which reduces energy loss due to resistance of transmission wires.
|
|
|
A device with a secondary coil having fewer loops than the primary coil, lowering the voltage created.
|
What is a Step-Down Transformer? (480)
|
Device found on electric lines near a house or business which reduces the amount of voltage of current to about 120V for surge protection and safety reasons.
|
