Magnetism

• What are the two poles of a magnet?

  North and South
• Where are magnetic forces strongest on a magnet?

  At the North and South Poles
• What happens when unlike poles of magnets are brought together?

  They attract each other
• What occurs when like poles of magnets are brought together?

  They repel each other
• What materials are always attracted to magnets?

  Magnetic materials
• Which elements are commonly found in magnetic materials?

  Iron, nickel, or cobalt
• What is the difference between hard and soft magnetic materials?

  Hard materials retain magnetism; soft lose it
• Why are soft magnetic materials used in electromagnets?

  They can be easily magnetized and demagnetized
• How can you determine if a material is magnetic or non-magnetic?

  Bring it close to a known magnet
• What does it indicate if a material is attracted but not repelled by a magnet?

  It is a magnetic material
• What does it indicate if a material is repelled by a magnet?

  It is a magnet
• What is magnetization?

  Inducing magnetism in magnetic materials
• What are the three methods to magnetize a material?

  Using a strong magnet, stroking, and direct current
• How can you magnetize a steel bar using a magnet?

  Stroke it with the magnet in one direction
• What happens to iron when it is magnetized by a strong magnet?

  It becomes a weak magnet
• What is the effect of stroking a steel bar with a magnet?

  It can create a permanent magnet
• What is the purpose of using direct current to magnetize a material?

  It creates a strong magnetic field
• What is demagnetization?

  Destroying the magnetism of a magnet
• What are the three methods to demagnetize a magnet?

  Heating, hammering, and alternating current
• How does heating a magnet affect its magnetism?

  It can demagnetize the magnet
• What happens when a magnet is hammered?

  It can lose its magnetism
• How does alternating current demagnetize a magnet?

  It generates a changing magnetic field
• What defines a magnetic field?

  Region where magnetic materials experience force
• What do magnetic field lines represent?

  Direction and strength of a magnetic field
• What is the direction of magnetic field lines?

  From North Pole to South Pole
• What does it indicate when magnetic field lines are close together?

  Strong magnetic field strength
• What does it indicate when magnetic field lines are far apart?

  Weak magnetic field strength
• What is a uniform magnetic field?

  Magnetic field strength remains constant
• How does the Earth's core contribute to its magnetism?

  It contains iron and nickel
• What direction do the Earth's magnetic field lines run?

  From South to North
• Why does a compass needle point to the North Pole?

  It is a magnet attracted to Earth's South Pole
• How can you plot magnetic field lines around a bar magnet?

  Using iron filings and paper
• What happens to the magnetic field lines as you move away from a wire carrying current?

  They get further apart
• What shape do the magnetic field lines around a current-carrying wire take?

  Concentric circles
• How does the right-hand grip rule help determine the direction of the magnetic field?

  Thumb points current direction, fingers field direction
• What happens to the magnetic field when the current direction is reversed?

  The magnetic field direction reverses
• What happens to the magnetic field strength inside a solenoid?

  It is strong and uniform
• How does increasing current affect the magnetic field strength?

  It increases the strength of the magnetic field
• What is the magnetic field pattern around a solenoid?

  Similar to that of a bar magnet
• How can a solenoid be turned into an electromagnet?

  By adding a soft iron core