Electrical Machines

IOE Electrical Machines, unit by unit: short interactive lessons with past-paper model answers.

Built on the Tribhuvan University IOE syllabus. Every topic explains the idea, works through the derivations and finishes with a model answer to a real past exam question.

Subjects

1. Magnetic Circuits and Induction

   Ohm's law for magnetic circuits, air gaps, B-H curve, hysteresis and eddy current loss, Faraday's law.

2. Transformer

   EMF equation, equivalent circuit, OC/SC tests, regulation, efficiency, instrument and three-phase transformers.

3. DC Generator

   Construction, commutator action, EMF equation, excitation, characteristics and efficiency.

4. DC Motor

   Working principle, torque, back EMF and the model answers IOE asks for.

5. Three Phase Induction Machines

   Rotating magnetic field, slip, torque equation and torque-slip curve, power stages.

6. Three Phase Synchronous Machines

   Alternator EMF, armature reaction, synchronous motor, starting and excitation.

7. Fractional Kilowatt Motors