Electrical Engineering

JEPPIAAR ENGINEERING COLLEGE
DEPARTMENT OF ELECTRICAL AND ELECTRONICS
131307-ELECTRICAL ENGINEERING-IMPORTANT QUESTIONS WITH ANSWER KEY
UNIT-1-DC GENERATORS
  1. EXPLAIN IN DETAIL ABOUT THE CONSTRUCTION OF DC GENERATOR WITH ITS CONSTRUCTION PARTS?
DIAGRAM:

  2. EXPLAIN IN DETAIL ABOUT THE CHARACTERISTICS OF DC MOTOR?

  3. EXPLAIN THE 3 POINT STARTER IN DETAIL

UNIT-2
TRANSFORMERS
  1. EXPLAIN IN DETAIL ABOUT THE CONSTRUCTION OF A TRANSFORMER?

  2. EXPLAIN THE EQUIVALENT CIRCUIT IN A TRANSFORMER?



  3. EXPALIN THE TRANSFORMER TESTS IN DETAIL?

UNIT-3
INDUCTION MOTORS
  1. CONSTRUCTION OF AN INDUCTION MOTOR









   

UNIT-4
SYNCHRONOUS AND SPECIAL MACHINES
  1. Principle of operation of synchronous motor?
Synchronous motors have the same construction as alternators. The few special features relative to the production of the direct current necessary for their excitation will be treated separately, later. It will be assumed that the reader is already familiar with the general details of construction of alternators

There are motors having movable armatures and stationary fields, or vice versa, and also motors with revolving iron masses in which all the windings are stationary. These machines are similar to the generators of the same types; for example, Fig. 1 indicates, diagrammatically, the principle of construction of a two-phase synchronous motor, with a ring armature and movable fields, receiving an exciting current through the brushes b1 and b2 .
These motors are designed like generators, the essential condition to be fulfilled being to have a low armature-reaction and powerful inducing fields, in order to obtain good stability.
Number of Poles
Although it is more difficult to increase the number of poles for small powers than for large powers, the construction of small synchronous motors for ordinary frequencies (40 to 60 cycles) presents no special difficulties, if the speeds...