electromagnets

• What does a solenoid do to the magnetic effect of a current?

  It increases the magnetic effect
• What is required to draw the magnetic field pattern for a straight wire?

  Understanding current flow and magnetic fields
• What happens when the switch in the circuit is closed?

  An electric current flows around the circuit
• What does the conventional current diagram represent?

  The flow of electric current in a circuit
• What is produced around a conducting wire when current flows through it?

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

  By using a compass
• What happens to the compass needle when the current is turned off?

  It lines up with the Earth's magnetic field
• What does a deflection of the compass needle indicate?

  There is a magnetic field around the wire
• What affects the strength of the magnetic field around a wire?

  The size of the current
• How does the distance from the wire affect the magnetic field strength?

  The strength decreases as distance increases
• What happens if the direction of the current is changed?

  The direction of the magnetic field changes
• How do you determine the direction of the magnetic field produced by a wire?

  Using the right hand grip rule
• What shape is formed when the wire is coiled?

  A solenoid
• What type of magnetic field does a solenoid produce?

  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 do you find the direction of the magnetic field in a solenoid?

  Using the right hand grip rule
• What increases the strength of the magnetic field in a solenoid?

  Increasing the size of the current
• What happens when the number of turns of the coil in a solenoid is increased?

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

  A piece of iron placed inside the solenoid
• What is a solenoid with an iron core called?

  An electromagnet
• Why are electromagnets useful?

  We can change the strength of the magnetic field
• How can we turn an electromagnet on or off?

  By changing the size of the current