Background

Background Video

  • PK – 3rd grade: Have you ever taken a magnet and moved it close to a compass?  The needle on the compass moves and points toward the magnet. A motor uses a very similar process to change electricity into the rotation of the shaft of a motor.
    • 3-PS2-4 (PS2.B): Define a simple design problem that can be solved by applying scientific ideas about magnets.
  • 4th – 6th grade: A DC motor is composed of a magnet called the stator, a rotor called the armature, and a power source. Magnets have two poles, north and south. These poles are attracted to each other, north to south. Two of the same pole, however, will repel one another. When electricity flows through a piece of wire, a magnetic field in generated around the wire. By winding the wire around the armature, placing it near a magnet, and running electricity through the wire, we can cause the armature to spin.
    • 4-PS3-2: Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents.
  • Middle School: A DC motor is composed of a magnet called the stator, a rotor called the armature, and a power source. Magnets have two poles, north and south. These poles are attracted to each other, north to south. Two of the same pole, however, will repel one another. The power source provides a current to the armature, which is coiled in a loop at a right angle above the magnet. An electric current in a magnetic field will experience a force. The two sides of the looped armature experience forces in opposite directions. The two forces create a turning influence, called torque, to rotate the armature. The motor’s speed depends on the amount of current in the wire, the length of the wire (number of loops), and the size of the magnetic field. Increasing one or all of these will make the motor spin faster.
    • MS-PS2-3: Ask questions about data to determine the factors that affect the strength of electric and magnetic forces.
    • MS-PS2-5: Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact
  • College:   A DC motor is composed of a permanent magnet called the stator, a rotor called the armature, and a power source. Magnets have two poles, north and south. These poles are attracted to each other, north to south. Two of the same pole, however, will repel one another. A permanent magnet will retain its magnetic properties in the absence of an inducing field or a current. The power source provides a current to the armature, which is coiled in a loop at a right angle above the magnet. An electric current in a magnetic field will experience a force perpendicular to the direction of the current. The two sides of the looped armature experience forces in opposite directions. This is because each side of the loop is perpendicular to the magnetic field produced by the magnet, but on opposite sides of the field. The two forces create a turning influence, called torque, to rotate the armature. The motor’s speed depends on the amount of current in the wire, the length of the wire (number of loops), and the size of the magnetic field. Increasing one or all of these will make the motor spin faster.