Electromagnetism

• What phenomenon does electromagnetism describe?

  Electric currents produce magnetic fields
• What shape do the magnetic field lines take around a wire with current?

  Concentric circles around the wire
• Where is the magnetic field strongest around a wire?

  Closest to the wire
• What determines the direction of the magnetic field around a wire?

  The direction of the electric current
• How can you remember the direction of the magnetic field using your hand?

  Use the right hand rule
• How do electric currents affect magnetic fields in wires?

  They produce their own magnetic fields around them
• What does curling your fingers in the right hand rule indicate?

  The direction of the magnetic field
• What direction does the magnetic field go for current flowing upwards?

  Anti-clockwise
• What happens to the magnetic field when current flows in the opposite direction?

  The magnetic field direction reverses
• What shape is formed when two wires are joined together with current flowing?

  A single flat circular coil
• How do the magnetic fields of a coil interact?

  They combine to form a single magnetic field
• What is a solenoid?

  A coil of wire with many turns
• What is the characteristic of the magnetic field within a solenoid?

  It is strong and uniform
• How does the magnetic field outside a solenoid compare to that of a bar magnet?

  It resembles the field of a bar magnet
• What do we call a magnet created by electricity?

  Electromagnet
• What happens to an electromagnet when the current is turned off?

  The magnetic field disappears
• How can you reverse the direction of an electromagnet's magnetic field?

  By reversing the current direction
• What happens to the magnetic field lines when the current direction is flipped?

  The direction of the field lines flips
• What is the first way to increase an electromagnet's strength?

  Increase the current flowing through it
• What is the second way to increase an electromagnet's strength?

  Increase the number of turns in the coil
• What is the third way to increase an electromagnet's strength?

  Decrease the length of the coil
• What is the fourth way to increase an electromagnet's strength?

  Add an iron core inside the solenoid
• Why does adding an iron core increase the strength of an electromagnet?

  Iron becomes an induced magnet when current flows
• What happens to the iron core's magnetism when the current is turned off?

  It loses its magnetic field
• What are the key characteristics of electromagnetism?

  • Electric currents produce magnetic fields
  • Magnetic field direction depends on current direction
  • Electromagnets can be turned on and off
  • Electromagnets can have their strength adjusted
• What are the methods to increase the strength of an electromagnet?

  1. Increase the current
  2. Increase the number of turns in the coil
  3. Decrease the length of the coil
  4. Add an iron core