Circuit Theory NOV-DeC 2014
Circuit Theory NOV-DeC 2014
Circuit Theory NOV-DeC 2014
2KWh in 30 mins
at 120V.What is the current drawn by the appliances?
(ANNA UNIV NOV-DEC 2014)(Reg 2013)
2. Calculate the equivalent resistance between the
terminals a and b Fig.1(ANNA UNIV NOV-DEC 2014)
(Reg 2013)
2014)(Reg 2013)
(b)Find the current through 5 resistor using superposition
theorem, in the circuit shown in Fig.8. (16) (ANNA UNIV NOV-
(Reg 2013)
Unit 1
1. An electrical appliances consumes 1.2KWh in 30 mins
at 120V.What is the current drawn by the appliances?
(ANNA UNIV NOV-DEC 2014)(Reg 2013)
2. Calculate the equivalent resistance between the
terminals a and b Fig.1(ANNA UNIV NOV-DEC 2014)
(Reg 2013)
11. (a) (i) Using node analysis, find the node voltages and
the currents through all resistors for the circuit shown in
Fig.4. (12) (ANNA UNIV NOV-DEC 2014)(Reg 2013)
Unit 2
1. Calculate the value of IN for the circuit shown in Fig.2.
(ANNA UNIV NOV-DEC 2014)(Reg 2013)
2014)(Reg 2013)
(b)Find the current through 5 resistor using superposition
theorem, in the circuit shown in Fig.8. (16) (ANNA UNIV NOVDEC 2014)(Reg 2013)
Unit 3
1. Calculate the total inductance of the circuit, if the
coefficient of coupling (k) between the two coils is
0.6,as shown in Fig.3. (ANNA UNIV NOV-DEC 2014)(Reg
2013)
Unit 4
1. A coil resistance 2.2 and an inductance 0.01H is
connected in series with a capacitor across 220V
mains. Find the value of capacitance such that
maximum current flows in circuit at frequency of
190Hz.Also find the maximum current. (ANNA UNIV
NOV-DEC 2014)(Reg 2013)
2. A 50F capacitor is discharged through a 100K
resistor. If the capacitor is initially charged to
400V,determine the initial energy. (ANNA UNIV NOVDEC 2014)(Reg 2013)
14(a)(i) For a magnetically coupled circuit, derive the
expression for mutual inductance (m) in terms L1 and L2. (6)
(ANNA UNIV NOV-DEC 2014)(Reg 2013)
(ii) For the coupled circuit shown in Fig.10. Find the value of
V2 so that the current I1=0. (10) (ANNA UNIV NOV-DEC 2014)
(Reg 2013)
Unit 5
1. Write the equations for the phasor difference between
potentials of the delta-connected networks. (ANNA
UNIV NOV-DEC 2014)(Reg 2013)
2. Three coils, each having a resistance of 20 and an
inductive reactance of 15 are connected in star to a
400V, 3-phase, and 50Hz supply. Calculate (a) the line
current, (b) power factor, and (c) power supplied.
(ANNA UNIV NOV-DEC 2014)(Reg 2013)
15. (a) Show that three-phase power can be measured by
two wattmeters. Draw the phasor diagrams. Derive an
expression for power factor interms of wattmeter readings.
(16) (ANNA UNIV NOV-DEC 2014)(Reg 2013)
(b)(i)A 400V (line to line) is applied to three star connected
identical impedances each consisting of a 4 resistance in
series with 3 inductive reactance. Find the (1) line current
(2) total power supplied (8) (ANNA UNIV NOV-DEC 2014)(Reg
2013)
(ii) Three star-connected impedances Z1=(20+j37.7) , per
phase are in parallel wit three delta-connected impedances
Z2=(30-j159.3) per phase. The line voltage is 398 volts.
Find the line current, power factor, power and reactive voltampere taken by the combination. (8) (ANNA UNIV NOV-DEC
2014)(Reg 2013)