electricity and magnets

• What type of force is

  magnetism?

  non-contact force
• Which metals are magnetic?

  iron, nickel and colbalt
• What are the two names of poles in a magnetic field

  north and south poles
• A bar magnet is a_________magnet. Fill in the blank

  perminent
• An electromagnet is a_________magnet. Fill in the blank

  temporary
• What are the three things in an electromagnet

  iron core, solenoid, power pack
• What does the iron core do 


  It is a magnetic metal so it creates a magnetic field
• What is the solenoid 


  It is a wire that wraps around the iron core
• What does the power pack do

  It gives power to the wire and makes a powerful magnetic field when turned on
• List the factors than can affect the strength of

  an electromagnet:

  • current

  • number of turns

  • add an iron core
• What does current mean and what are its units called.

  Rate of flow of charge, Amps ( A)
• What is voltage and what are its units called

  The size of the ‘push’ that causes current to flow around a

  circuit. Volts (V)
• What is resistance and what are its units called

  A measure of the opposition to current flow in an

  electrical circuit (components provide resistance in a

  circuits). ohms (Ω)
• What force causes a static charge to build up?

  friction
• A teacher rubs a balloon on her jumper. The

  electrons on the jumper move onto the balloon. The jumper becomes - The balloon becomes -

  The jumper becomes positively charged and the balloon becomes negatively charged
• What happens to the

  current (and

  brightness) when

  another bulb is

  added in series:

  The current is

  reduced because the

  resistance of 2 bulbs

  is higher. This

  means the bulbs are

  less bright.
• What happens to

  the current (and

  brightness) when

  another bulb is

  added in parallel:

  The current for each

  ‘loop’ remains the

  same as if there were

  only one loop. This

  means the bulbs are

  the same brightness,

  and the cell is used up

  quicker.