10116
Reg. No. Name

FIRST SEMESTER B.TECH DEGREE EXAMINATION, JANUARY 2016
Course Code: BE101-03 Course Name: INTRODUCTION TO ELECTRICAL
ENGINEERING

Max. Marks: 100 Duration: 3 Hours

Instructions: Make suitable assumptions if any data is missing
Write units in all numerical answers

PART- A
Answer all Questions. IOx4 = 40 marks

Draw and explain the characteristics ofideal and practical voltage and current sources.

2 Using star-delta transformations, find the total resistance REQ for the circuit shown below.

1kO
‏و سا‎ ಖು
Wy
200Q 30002
Reo 1.5kQ
‏سے‎ ⋅ 12kQ

3 What is fringing रटलं and leakage flux in magnetic circuit? What are its disadvantages?

An alternating current is represented by i(t) = 200sin(3 14t). Find (1) RMS value (ii)
frequency

(iii) time period and (iv) instantaneous value of voltage when t 3msec.

5 From the figure shown below, (i) evaluate current '1' flowing through the circuit and (11)
draw the phasor diagram ofcurrent and voltage Cake source
voltage as reference quantity).

| 20 +30 10000
10000 1:

6 Achoke coil takes 3A which is lagging 60° with respect to applied voltage of 230 V, 50 Hz
AC supply. Determine impedance, resistance. and inductance of coil.
List a few advantages of three phase system over single phase system.
Three impedances (10+j15) Q are connected in delta across three phase 400 V supply. Find

the line current, power factor and active power.

9 Explain the necessity of earthlings in electrical installations

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