Alternators, Dynamos & Oscilloscopes

• What is the principle behind electromagnetic induction?

  Generating electric current by moving a wire
• What are alternators and dynamos classified as?

  Generators
• How do generators produce electricity?

  From rotational motion of a coil of wire
• What is the key difference between dynamos and alternators?

  • Dynamos use a split ring commutator
  • Alternators use slip rings and brushes
• What type of current do dynamos produce?

  Direct current
• What type of current do alternators produce?

  Alternating current
• What happens when the coil of wire rotates relative to the magnets in an alternator?

  A magnetic field induces voltage and current
• Why do slip rings and brushes in alternators prevent wrapping during rotation?

  They allow continuous contact without interruption
• What does the oscilloscope visualize in an alternator?

  The alternating potential difference and current
• How does the speed of the coil rotation affect the alternating current in an alternator?

  Faster rotation increases peak height and frequency
• What happens when the coil of wire spins relative to the magnet in a dynamo?

  A magnetic field induces voltage and current
• What is the role of the split ring commutator in a dynamo?

  It swaps contacts every half turn
• Why is direct current always positive on an oscilloscope graph?

  Because it flows in the same direction
• How does the speed of rotation affect the oscillations in a dynamo?

  Faster rotation increases peak size and frequency