Chapter 1: Fundamental Concept

  • Fundamental of Electrical Motors
  • How electric current develops mechanical force & torque
  • How to supply electric current to the rotating coil
  • How to maintain the direction of current flowing through conductors
  • Important role of Faraday’s law and Lenz’s law in energy conversion (Back emf)

Chapter 2: Mathematical Representation

  • How to get desired torque and speed from motor
  • Graphical Representation of Torque-Speed equation

Chapter 3: Speed Control of DC Motor

  • Effect of Supply Voltage on motor speed
  • Effect of adding resistance to the armature winding on motor speed
  • Effect of adding resistance to the field winding on motor speed

Chapter 4: More About DC motor

  • Controversy effect of field flux on motor torque developed
  • Equation of force & torque
  • Shape and equation of back emf
  • Average value of back emf
  • Power transfer
  • DC series motor
  • Shaft torque
  • Applications and limitations


  • Faraday’s law
  • Lenz’s law
  • Screw rule
  • Ohm’s law