Electromagnetism

• What phenomenon do electric currents produce?

  Magnetic fields
• How do electric currents create magnetic fields?

  By flowing through wires and coils
• What happens to the magnetic field when current flows through a wire?

  It produces concentric circles around the wire
• What does the strength of the magnetic field depend on in a wire?

  Proximity to the wire
• What is the right hand rule used for?

  To determine the direction of the magnetic field
• How do you use the right hand rule for current flowing upwards?

  Thumb up, fingers curl anti-clockwise
• What happens to the magnetic field if the current direction is reversed?

  The magnetic field direction also reverses
• What occurs when two wires with opposite current directions are joined?

  Magnetic fields form ellipses and combine
• What is a solenoid?

  A coil of wire with multiple turns
• How does the magnetic field behave inside 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 is an electromagnet?

  An electric current creates a magnet
• 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 are the four ways to increase an electromagnet's strength?

  Increase current, turns, decrease length, add iron core
• Why does adding an iron core increase an electromagnet's strength?

  Iron becomes an induced magnet when powered
• What happens to the iron core when the current is turned off?

  It loses its magnetic field