Electromagnetism

• What phenomenon does electromagnetism describe?

  It describes how electric currents produce their own magnetic fields.
• How does an electric current affect the magnetic field around a wire?

  The electric current produces a magnetic field represented by concentric circles around the wire.
• What shape do the magnetic field lines take around a wire with current flowing through it?

  The magnetic field lines are concentric circles around the wire.
• Where is the magnetic field strongest around a wire?

  The magnetic field is strongest closest to the wire.
• How can you determine the direction of the magnetic field around a wire using your hand?

  You can use the right hand rule by curling your fingers in the direction of the magnetic field while your thumb points in the direction of the current.
• What does the right hand rule help you remember?

  It helps you remember the direction of the magnetic field based on the direction of the current.
• What happens to the direction of the magnetic field if the current direction is reversed?

  The direction of the magnetic field also reverses when the current direction is reversed.
• What occurs when two wires with currents in opposite directions are joined together?

  The magnetic fields will interact and form a single magnetic field through the center of the coil.
• What is a solenoid?

  A solenoid is a long coil of wire with many turns that creates a strong and uniform magnetic field when current flows through it.
• How does the magnetic field of a solenoid compare to that of a bar magnet?

  The magnetic field of a solenoid is similar to that of a bar magnet, with distinct north and south poles.
• What happens to an electromagnet when the current is turned off?

  The magnetic field disappears when the current is turned off.
• How can the direction of the magnetic field in an electromagnet be reversed?

  The direction of the magnetic field can be reversed by reversing the direction of the current flowing through the wire.
• What is one limitation of small electromagnets?

  Small electromagnets produce a very weak magnetic field.
• What are the four ways to increase the strength of an electromagnet?

  • Increase the current flowing through the solenoid
  • Increase the number of turns in the coil
  • Decrease the length of the coil while keeping the number of turns the same
  • Add an iron core to the inside of the solenoid
• Why does adding an iron core to a solenoid increase its strength?

  Iron is a soft magnetic material that becomes an induced magnet when the solenoid is switched on, increasing the magnetic field strength.
• What happens to the iron core when the current is turned off?

  The iron core loses its magnetic field as soon as the current is turned off.
• What is the main takeaway from the video on electromagnetism?

  Electricity can be used to create a magnet, known as an electromagnet, which can be turned on and off.