Electromagnets

• What should you be able to describe by the end of the video?

  How current generates a magnetic field
• How does a solenoid affect the magnetic effect of a current?

  It increases the magnetic effect of the current
• What can you draw related to a straight wire and a solenoid?

  The magnetic field pattern for both
• What happens when the switch in the circuit is closed?

  An electric current flows around the circuit
• What does the diagram show when the current flows through a wire?

  A magnetic field is produced around the wire
• How can we prove the existence of a magnetic field around a wire?

  By using a compass
• What does the compass needle do when the current is turned on?

  It deflects, indicating a magnetic field
• What happens to the strength of the magnetic field as you move away from the wire?

  The strength decreases as you move away
• What happens if the direction of the current is changed?

  The direction of the magnetic field changes
• What rule is used to determine the direction of the magnetic field produced by a wire?

  The right hand grip rule
• How do you position your right hand to use the right hand grip rule?

  Thumb points current direction, fingers field direction
• What shape does coiling the wire create?

  A solenoid
• What type of magnetic field does a solenoid produce when current is turned on?

  A strong and uniform magnetic field
• How does the magnetic field around a solenoid compare to that of a bar magnet?

  It has a similar shape
• How can you determine the direction of the magnetic field in a solenoid?

  Using the right hand grip rule
• What are the three ways to increase the strength of the magnetic field in a solenoid?

  Increase current, turns, or add iron core
• What happens to the magnetic field strength if the current size is increased?

  The strength of the magnetic field increases
• How does increasing the number of turns in the coil affect the magnetic field?

  It increases the strength of the magnetic field
• What is an iron core in a solenoid called?

  An electromagnet
• Why are electromagnets useful?

  We can change their magnetic field strength
• What can be done to turn an electromagnet on or off?

  Change the size of the current
• What are the key concepts related to current and magnetic fields?

  • Current generates a magnetic field
  • Magnetic field strength depends on current size
  • Direction of magnetic field changes with current direction
  • Solenoids increase magnetic field strength
  • Electromagnets can be turned on/off
• What are the methods to increase the strength of a solenoid's magnetic field?

  1. Increase the size of the current
  2. Increase the number of turns of the coil
  3. Place an iron core inside the solenoid
• How does the right hand grip rule help in understanding magnetic fields?

  • Thumb points in the direction of conventional current
  • Fingers curl in the direction of the magnetic field
  • Helps visualize magnetic field direction around wires and solenoids