DC motor. Image credit kostov-motors.com

ZIMSEC O Level Combined Science Notes: Experiment: Demonstrating that an electric wire moves in a magnetic field

  • A DC motor converts direct electric current into kinetic energy
  • It has a stator
  • Stator-a stationary magnet found within a DC motor
  • It also has a many coils wound on an armature
  • This is called a rotor
  • The coils are mounted on an axle which rotates in a magnetic coil
The internal components of a DC Motor. Image credit blogspot.com

The internal components of a DC Motor. Image credit blogspot.com

  • Each end of the coil is connected to the half of a split ring
  • The split ring is also known as a commutator
  • The commutator turns with the coil and makes contact with the two¬†carbon brushes
  • That it press lightly against the commutator split rings
  • Current is fed into the coil through the carbon brushes
  • The coil rotates until it is in vertical position
  • Its momentum (inertia) carries it past the vertical position
  • The two halves change contact from one brush to another
  • The direction of current is now reversed in the coil
  • The other half is also forced downwards thus maintaining rotation in one direction
  • Real world motors have a more sophisticated design but they still operate on the same principle
  • Some of these modifications include:
  • many turns in the coil,
  • A soft iron cylinder round which coils are wound
  • The coil and this core are known as an armature
  • A strong magnet
  • DC motors are used where variation in speed is needed
  • For example electric cars and trains
  • They are also used in toys and drones

Uses of Motors

  • Motors be they DC motors or AC motors (AC motors are beyond the scope of the O level syllabus) have a number of uses
  • They are used to drive devices such as:
  • pumps in mines and on farms
  • lifts in buildings
  • to power electric lawnmowers
  • electric drills
  • electric saws
  • Motors can also be found:
  • in fans
  • In washing
  • electric cars

To access more topics go to the Combined Science Notes page.

Quick NetOne, Telecel, Africom, And Econet Airtime Recharge

If anything goes wrong, chat with us using the chat feature at the bottom right of this screen