(Paper) Basic Electrical Engineering, May/June-2001 (MG University)

MG University
B. Tech Degree Examination, May/June 2001
First and Second Semester

Paper VIII – Basic Electrical Engineering
(Common for all branches)

Time: Three Hours                                                                                                                                                                   Maximum: 100 Marks

Answer all questions Each question carries 4 marks each
Part A

1

State and explain Kirchoff's voltage law.

2

State and explain Faraday’s Laws of Electromagnetic Induction.

3

Explain the concepts of phase and phase difference.

4

Discuss the stator parts of a D.C. machine briefly.

5

Discuss the cooling of transformers.

6

State the principle of operation of a 3–phase induction motor.

7

Discuss the application of moving iron instruments.

8

Discuss the working of a mercury vapour lamp.

9

Discuss the electric supply system for traction in India.

10

Discuss the advantages and disadvantages of overhead distribution systems.

Part B
Answer all questions Each question carry 12 marks each

11

a) Discuss the concept of electric current flow, electromotive force and power conversion.
b) 3 batteries P, Q and R consisting of 50, 55 and 60 cells in series supply in parallel, a common load of 100 Amps. Each cell has internal EMF of 2 Volts and a internal resistance of 0.005 ohm. Determine the current supplied by each battery and the terminal voltage.

Or

12

a) Discuss the production of statically and dynamically induced EMF.
b) Two coils having 50 and 500 turns respectively are wound on a closed iron circuit of section 50 sq.cm and mean length 120 cms. Estimate the mutual inductance between the coils and each self inductance. The relative permeability of iron is 1000.

13

a) Discuss the importance of RMS value of an AC wave? What is form factor?
b) Four coils are connected in series. Each has an induced EMF of 100 Volts, 50 HZ, but with a phase different of 14 degrees between them. What is the effective value of the total EMF?

Or

14

a) Discuss the features of a balanced three phase system.
b) Discuss the relationship between line and phase values of currents in a balanced star and delta connected systems.

15

a) Derive the EMF equation of a D.C. Generator.
b) Discuss the various classifications of D.C. generators.

Or

16

a) What are the losses in transformer? How these can be experimentally determined?
b) Discuss the working principle of a 3–phase induction motor.

17

a) Explain with neat sketches the working of moving coil instruments.
b) Explain the selection criteria for traction motors.

Or

18

a) Discuss the working and parts of the induction type energy meter.
b) With a neat diagram explain the working of the fluorescent tube circuit.

19

a) Compare hydro-electric and thermal power generations.
b) Discuss the advantages of High Voltage transmission.

Or

20

a) What are the criteria for selection of a distribution voltage?
b) Draw a one line diagram of a typical power system and name the parts.