QUESTIONS AND ANSWERS

( ELECTRICAL SUPERVISOR EXAMINATION )

1-PRINCIPLES OF ELECTRICITY:

1. compare the pressure, current, and resistance with water analogy
2. State Kirchhoff's Laws.
3. What are the rules of Resistance of electrical conductor?  What is meant by "Specific Resistance" and what is the unit of specific resistance?
4. What is the effect of temperature on resistance? What is temperature-coefficient?
5. Define the Current, Resistance, Voltage, Wattage and Energy and give their units.
6. What is Inductance and Self-Inductance and determine the equation of Induced e.m.f.
7. Explain the  principle  of a Capacitor. Give its unit and explain its reactance.
8. Explain the magnetic effect, electrical effect, and heating effect of current with examples.
9. What is the relationship between electrical and mechanical power?
10. Example on power factor improvement.

2-ALTERNATOR AND SYNCHRONOUS MOTOR:

1. Describe the constructional features of salient pole of an alternator with diagram.
2. Describe the constructional features of Cylindrical Rotor of an alternator with diagram.
3. What is Synchronous Reactance?
4. How may the voltage of an alternator be regulated?
5. Describe the constructional features of slip rings of an Alternator with diagram.
6. Describe the constructional  features of stator of an Alternator with diagram.
7. Exercise
8. Exercise

3-DIRECT CURRENT GENERATOR:

1.  How may the D.C. Generator be classified as per their exciatation.
2. How may the characteristic of a D.C.Generator be obtained?
3. With reference to D.C.Machine explain the phenomenon of Armature Reaction.
4. Describe the commutation process of D.C.Generator.
5. What is Reactance Voltage? What is the effect of commutation on inductance of coil.?
6. Describe the methods of reducing spark on brush holder during commutation.
7. How is the kilowatt load adjusted between D.C.Shunt Generators?
8. How is the sharing of kilowatt load between over excited and under excited shunt generators?
9. How is the kilowatt load adjusted between compound generators?

4-TRANSFORMER:

1. Describe the working principle of Auto Transformer.
2. Describe the type of transformer windings.
3. What are the conditions for operating three phase transformers in parallel?
4. Explain the method of determining regulation with the help of Dr. Cap's diagram.
5. Describe the losses of transformer.
6. Determine the relation between voltage and current of transformer.
7. How is the V-V connection be completed of transformer windings?
8. How is the Scot or T-T connection be completed of transformer windings?
9. Exercise on parallel operation of the transformers.

5-DIRECT CURRENT MOTOR:

1. Describe the Metadyne Generator.
2. How may the speed of a D.C.Shunt Motor be controlled?
3. How may the speed of a D.C.Series Motor be controlled with the help of flux of the motor?
4. Describe the breaking method of a D.C.Series Motor.
5. Describe the electrical breaking method of a D.C.Shunt Motor.
6. How many type of windings are used in D.C.Compound Motor?
7. Describe the characteristics curve of D.C.Series Motor.
8. Describe the characteristics curve of D.C.Shunt Motor.

1. State Fleming's Right Hand and Left Hand Rules.
2. Explain the Mutual Inductance and coefficient of coupling.
3. What is self inductance and coefficient of self inductance?
4. State Laws of Faraday's. What is mint by Statically and Dynamically induced e.m.f.?
5. Explain the lifting power of a magnet.
6. What is the effect of magnetic field on a conductor carrying current?
7. Explain the hysteresis loop of magnetic material.
8. What is reluctance?
9. Describe the series and parallel magnetic circuit with the diagram.
10. Describe with a neat sketch the distribution of flux in straight and circular conductor?
11. Explain the flux density, magnetic field strength and permeability.

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