Register Number

SATHYABAMA UNIVERSITY(Established under section 3 of UGC Act,1956)

Course & Branch :B.E - E&C/ECE/EEE/EIE/ETCETitle of the Paper :Basic Electrical Engineering Max. Marks:80Sub. Code :SEEX1001 (2010-2011) Time : 3 HoursDate :05/06/2012 Session :FN______________________________________________________________________________________________________________________

PART - A (10 x 2 = 20) Answer ALL the Questions1. State Kirchhoff’s law.

2. Define Electric potential.

3. State Lenz’s law.

4. Define Magnetomotive force and Reluctance.

5. Calculate RMS value of Half Wave Rectifier.

6. What is a Reactive power? Write its unit.

7. What is a megger?

8. Why damping Torque is necessary in indicating instruments.

9. Give different types of wiring system adopted in house wiring.

10. Draw the wiring diagram of fluorescent lamp.

PART – B (5 x 12 = 60)Answer All the Questions

11. For the network shown in fig Q.11, determine the current I through the resistance connected between the terminal A & B (All resistances are in ohms).

(or)12. Fig Q.12 shows a number of resistances connected in delta and

star. Find the resistance across the terminal A and B. Use star/delta conversion method.

13. (a) Compare Magnetic and Electric circuits. (b) An air cored toroidal coil has 480 turns, a mean length of

30cm and a cross-sectional area of 5cm2. Calculate (i) an inductance of coil and

(ii) the average induced emf, if a current of 4A is reversed in 60 milliseconds.

(or)14. (a) State and explain Faradays laws of Electromagnetic

induction?(b) The air gap in magnetic circuits is 1.5 mm long and 2500 mm2

in cross sectional area. Calculate the reluctance of the air gap.

15. Find the RMS Value and Average valve of the trapezoidal current wave form shown in fig Q.15

ig Q.15

(or)16. A coil has a resistance of 5Ω and an inductance of 31.8mH.

Calculate the current taken by the coil and power factor when connected to 200v, 50Hz supply.(a) Draw the vector diagram.

(b) If a non-inductive resistance of 10Ω is then connected in series with coil, calculate the new valve of current and its power factor.

17. Explain the following with reference to the indicating instruments(a) Deflecting torque(b) Controlling torque(c) Damping torque

(or)18. Explain the working principle of Moving Coil Voltmeter and

ammeter with neat diagram.

19. What is the necessity of earthing in domestic wiring? Discuss in brief the various methods of earthing.

(or)20. (a) Draw the one line diagram of a typical power supply system.

(b) Discuss about the Do’s and Don’ts of electrical safety.