010BE10103092007 Pages: 3

Reg No.: Name:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
B.Tech Degree S1,S2(S,FE) Examination May 2021 (2015 Scheme)

Course Code: BE101-03
Course Name: INTRODUCTION TO ELECTRICAL ENGINEERING

Max. Marks: 100 Duration: 3 Hours
PARTA
Answer all questions, each carries 4 marks Marks
1 State and explain Faradays laws of Electromagnetic induction. (4)
2 Distinguish between self and mutual inductances. Derive an expression for the (4)

Self-inductance of a coil.

3 Explain Kirchhoff’s law. (4)

4 Compare Electric and magnetic circuits. (4)

5 Derive an expression for energy stored in a magnetic circuit. (4)

6 Derive the form factor of a pure sinusoidal wave form. (4)

7 Define bandwidth of a resonant circuit. Give the relationship of quality factor (4)
in terms of bandwidth and resonant frequency.

8 A resistance of 10Q and an inductive reactance of 10Q are connected in series. (4)
Calculate the value of impedance and draw the impedance triangle.

9 The input power to a three phase motor was measured using two watt meters. (4)
The readings were 5.2 KW and — 1.7 KW, and the line voltage was
415V.Calculate a) the total power b) the power factor c) the line current

10 What are the advantages of three phase system. (4)

PART ‏ا‎
‎Answer any four full questions each carries 10 marks
11 a) An iron cored reactor is wound with 250 turns and has an air gap of 0.8 cm. (6)
The flux path in iron is 1.2 m and the cross sectional area is 0.15 m2
Determine the inductance of the reactor when carrying a current of 10 A. Take
relative permeability of iron as 1100.

b) Explain ideal and non-ideal voltage sources. (4)

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