electromagnets

• What happens when a current flows through a conducting wire? 

  A magnetic field is produced around the wire
• How can you demonstrate the presence of a magnetic field around a current-carrying wire?

  Use a compass; the needle deflects when the current is on.
• How does the strength of the magnetic field around a wire depend on the current?

  A larger current produces a stronger magnetic field.
• How does the strength of the magnetic field around a wire change with distance from the wire?

  It decreases as you move further from the wire.
• What happens to the magnetic field direction if you reverse the current direction?

  The magnetic field's direction also reverses.
• What rule is used to determine the direction of the magnetic field produced by a wire?

  The right-hand grip rule.
• How does the right-hand grip rule work for a straight wire?

  Thumb points in the conventional current direction; fingers curl in the magnetic field direction.
• What is a solenoid?

  A coil of wire.
• What kind of magnetic field does a solenoid produce?

  A strong, uniform magnetic field inside.
• What kind of magnetic field does a solenoid produce?

  A strong, uniform magnetic field inside.
• What is the shape of the magnetic field around a solenoid?

  Similar to that of a bar magnet.
• How does the right-hand grip rule apply to a solenoid?

  Fingers curl in the conventional current direction; thumb points to the north pole.
• Name three ways to increase the magnetic field strength of a solenoid.

  Increase current, increase number of turns, add an iron core.
• What is an electromagnet?

   A solenoid with an iron core.
• What is the advantage of an electromagnet?

  Its magnetic field strength can be controlled by changing the current; it can be turned on or off.
• How does increasing the current in a solenoid affect its magnetic field?

  It increases the magnetic field strength.
• What is the conventional current?

  The direction of current flow considered historically, from positive to negative terminal.
• What is the significance of the conventional current in applying the right-hand grip rule?

  The direction of the conventional current determines the thumb's direction in the right-hand grip rule.
• What is the difference between the magnetic field around a straight wire and a solenoid?

  A solenoid's magnetic field is stronger, more uniform inside, and resembles a bar magnet's field.
• How does increasing the number of turns in a solenoid affect its magnetic field?

  It increases the magnetic field strength.