Electromagnetism

• Electromagnetism


  The phenomenon whereby electric currents produce their own magnetic fields
• How electromagnetism works

  1. Electric current in a wire produces a magnetic field around the wire

  2. Magnetic field lines are concentric circles around the wire

  3. Magnetic field is strongest closest to the wire

  4. Direction of magnetic field depends on direction of current flow
• Right hand rule


  Used to determine the direction of the magnetic field around a current-carrying wire
• Magnetic field around a coil

  1. Magnetic fields from each side of the coil combine to form a single magnetic field running through the center of the coil

  2. More turns in the coil creates a solenoid with a strong, uniform magnetic field inside
• Electromagnet


  A magnet created by an electric current flowing through a coil of wire
• Electromagnets


  • Can be turned on and off by controlling the current
  • Can reverse the direction of the magnetic field by reversing the current direction
• Ways to increase electromagnet strength

  • Increase the current flowing through the coil
  • Increase the number of turns in the coil
  • Decrease the length of the coil
  • Add an iron core inside the coil
• Iron core increases the strength of the electromagnet's magnetic field, but the field disappears when the current is turned off
• Electric charges can be positive or negative.
• A moving charge produces an electric current, which generates a magnetic field around it.
• A moving charge produces an electric current, which generates a magnetic field around it.
• The force between two charged objects depends on their charge and distance apart.
• Like charges repel; unlike charges attract.
• An object with no net charge has equal amounts of positive and negative charge.
• An object with no net charge has equal amounts of positive and negative charge.
• Conductors are materials that allow electricity to flow easily, such as metals like copper and aluminum.
• Charge is conserved - it cannot be created or destroyed.
• Conductors are materials that allow electricity to flow easily, such as metals like copper and aluminum.
• Charge is conserved - it cannot be created or destroyed.
• Like charges repel each other, while unlike charges attract.
• Like charges repel each other, while unlike charges attract.
• The magnitude of the Lorentz Force depends on the distance between the wires, the speed at which the current flows, and the angle between the wires and the current.
• The magnitude of the Lorentz Force depends on the distance between the wires, the speed at which the current flows, and the angle between the wires and the current.
• If the current flows in opposite directions, the forces attract; otherwise, they repel.
• If the current flows in opposite directions, the forces attract; otherwise, they repel.
• When two wires carrying current are placed close together, they create a force between them called the Lorentz Force.
• When two wires carrying current are placed close together, they create a force between them called the Lorentz Force.
• When two wires carrying current are placed close together, they create a force between them called the Lorentz Force.
• The right-hand rule states that if your thumb points in the direction of the current flow, then your fingers curl in the direction of the magnetic field lines.
• The right-hand rule states that if your thumb points in the direction of the current flow, then your fingers curl in the direction of the magnetic field lines.
• The right-hand rule states that if your thumb points in the direction of the current flow, then your fingers curl in the direction of the magnetic field lines.
• Conductors are materials that allow electricity to flow through them easily.
• Conductors are materials that allow electricity to flow through them easily.
• Conductors are materials that allow electricity to flow easily, such as metals like copper and aluminum.
• The right-hand rule states that if your thumb points in the direction of the current flow, then your fingers curl in the direction of the magnetic field lines.
• The electric field around an isolated charged particle is spherical.
• Insulators are materials that do not conduct electricity well, such as rubber or plastic.
• The force between two charged objects depends on the distance between them.
• Electric fields are produced by charged objects and can exert forces on other charged objects.
• Electric fields are produced by charged objects and can exert forces on other charged objects.