Magnetism and electromagnetism

• What is an alternator?

  A device generating alternating current
• What happens when opposite poles of magnets are near each other?

  They experience a force of attraction
• What is generated around a current-carrying wire?

  A magnetic field
• What is a dynamo?

  A device generating direct current
• How does an electric motor operate?

  It uses a current-carrying coil in a magnetic field
• What is an electromagnet?

  A solenoid with an iron core
• What does Fleming’s Left-Hand Rule determine?

  The orientation of force, current, and magnetic field
• What is the generator effect?

  Induction of potential difference with motion
• What is an induced magnet?

  A material that becomes a magnet temporarily
• What does a magnetic compass do?

  Points in the direction of Earth's magnetic field
• What do magnetic field lines represent?

  The strength and direction of a magnetic field
• What is a magnetic field?

  The region where magnetic forces act
• What are magnetic poles?

  Regions where magnetic forces are strongest
• How does a microphone work?

  It converts sound waves into electrical current
• What is the motor effect?

  A force experienced by a current-carrying wire in a magnetic field
• What is a permanent magnet?

  A magnet that produces its own magnetic field
• What happens when like poles of magnets are near each other?

  They experience a force of repulsion
• What is a solenoid?

  A wire wrapped into a coil shape
• How can the magnetic field strength of a solenoid be increased?

  By adding an iron core
• What is a step-down transformer?

  A transformer with lower secondary potential difference
• What is a step-up transformer?

  A transformer with higher secondary potential difference
• What is the unit of magnetic flux density?

  Tesla
• What is a transformer?

  An iron core with primary and secondary coils
• What are the two poles of a magnet?

  North and South Poles
• What happens when same poles of magnets are brought together?

  They repel each other
• What occurs when opposite poles of magnets are brought together?

  They attract each other
• What are permanent magnets?

  Always magnetic, always have poles
• What are induced magnets?

  Materials that become magnetic temporarily
• How can induced magnets be made?

  By stroking with a permanent magnet
• Which materials can become induced magnets?

  Iron, Nickel, Cobalt
• How do magnetic field lines behave?

  They point from North to South
• What happens to magnetic field strength with distance?

  Strength decreases with distance from the magnet
• What do plotting compasses show?

  The direction of the magnetic field
• Why does a compass point North?

  It aligns with Earth's magnetic field lines
• Where does the compass actually point?

  To Earth's magnetic South Pole above Canada
• Why is Earth's magnetic pole above Canada considered a magnetic South Pole?

  Because like poles repel each other
• What does current produce around a wire?

  A magnetic field
• How is the direction of the magnetic field around a wire determined?

  By the right hand grip rule
• What happens to the magnetic field strength with greater current?

  It becomes stronger
• What happens to the magnetic field strength with greater distance from the wire?

  It becomes weaker