electricalengineeringquestionanswer

Q:What do you mean by Economics of power generation?  The art of determining the per unit i.e. one KWh cost of production of electrical energy is  known as Economics of power generation.  2) Explain the term depreciation.  The decrease in the value of the power plant equipment and building due to constant use is known as depreciation. In practice, every power station has a useful life ranging from fifteen to thirty years. From  the time the power station is installed, its equipment steadily deteriorates due to wear  and tear so that there is a gradual reduction in the value of the plant. This reduction in  the value of plant every year is known as annual depreciation.  3) Define load factor.  Load factor is the ratio of average demand to the maximum demand during a certain  period of time and is applicable to both generating equipment and receiving equipment. Load factor = Average demand/Maximum demand  4) What is load curve?  ...

Q: State the types of Induction motor ? 1) Squirrel cage Induction motor 2) Wound or slip ring Induction motor. Q: Why skewing is done in squirrel cage Induction motor? i)    For more uniform torque ii)   Reduction in noise iii) To decrease magnetic locking tendency Q:What is the purpose of connecting external resistors to slip ring Induction motor? It increases starting torque and decreases starting current. Q.Can we add extra resistance in series with squirrel cage rotor? State the reason?  We cannot add extra resistance in series with the rotor because all the copper bars of the rotor are short circuited in both the sides by copper end rings to have a closed circuit. Q:State the difference between squirrel cage Induction motor and slip ring Induction motor. Parameters Squirrel cage IM Slip ring IM Rotor winding Copper bars are short circuited at both ends Three phase winding End ring present Absent Eff...

Q: What are the essential parts of DC machine? A: 1. Magnetic frame or yoke 2. Poles 3. Armature 4. Commutator 5. pole shoes 6.   armature windings 7. interpoles  8. Brushes 9. bearings 10. shaft Q. What is the purpose of yoke in d.c machine? 1.It acts as a protecting cover for the whole machine and provides mechanical support for the poles. 2.It carries magnetic flux produced by the poles Q. What is the purpose of Field pole in d.c machine? To produce flux with the help of field winding Q. What is the purpose of Field winding in d.c machine? To produce flux Q. What is the purpose of pole shoes in d.c machine? 1. They support field coil 2.Decrease reluctance 3.Increase cross section area of magnetic circuit Q. What is the purpose of Armature core in d.c machine? To store armature windings and provide the path for main flux Q. What is the purpose of Armature winding in d.c machine? To develop main electrical power Q. Why the armature core in d.c machines is constructed wit...