b)

b)

20 a)

D7082

PART C
Answer any one full question from each module, each carries 10 marks.
Module V
Define the terms band width and quality factor. Explain the significance of both.
Derive the resonance frequency of the circuit shown below.

Point out any four differences of series and parallel resonance.
Calculate the real power, reactive power, apparent power and power factor of the

circuit.
4൨ 13൨

100V, SOHz

Module VI
List the advantages of 3 phase ac over single phase ac.
A 3 phase 4 wire star connected load of phase impedances 21 = (16 + 112) Q, 7) =
(14 - 121) ೧ and 23 = 25 വട connected across a 254 ۷, 50 Hz ac supply. Calculate
the current in each phase of the load and power consumed by the load.
Describe how the two watt meter method is used for real and reactive power
measurement in a 3phase 3 wire circuit.
A 3 phase balanced load connected across a 3 phase 400V ac supply draws a line
current of 10 A. Two wattmeters are used to measure input power. The ratio of two

wattmeter readings is 2:1. Find the readings of the two wattmeters.
KK

Page 3 of 3

(4)
(6)

(4)
(6)

(4)
(6)

(6)
(4)