I B.Tech - Regular Examinations, June 2009
First Year
ELECTRICAL CIRCUITS ANALYSIS- SET NO: 3
(Regulation 2007)
Time : 3 hours |
Maximam Marks:80 |
Answer any FIVE Questions
1. (a) State and explain Kirchhoff’s laws.
(b) A Wheatstone bridge ABCD is arranged as follows, AB=10
, BC=30
,
CD=15
and DA=20
. A 2V battery of internal resistance 2
is connected
between A and C with A positive. A galvanometer of resistance 40
is con-
nected between B and D. Find the magnitude and direction of galvanometer
current.
2.(a)Two long single layer solenoids have the same length and the same number of turnsbut are placed co-axially one with in the other.The diameter of the inner coil is
8cm and that of the outer coil is 10cm. Calculate the co-efficient of coupling.
3. (a)Why the rms values of an alternating quantity is more important than its averagevalue. Find the rms value of the resultant current in a conductor which carries simultaneously sinusoidal alternating current with a maximum value of 15A and direct current of 15A, by deriving necessary expressions.
4.(a)A symmetrical 3-phase, 3-wire, 440V supply is connected to a star connected load.The impedances in each branch are : Z1=(2+j3), Z2=(1-j2), Z3=(3+j4). Find its equivalent delta connected load. Hence find the phase and line currents and the total power consumed in the circuits.
5.(a) Discuss on the dot method of obtaining a dual network.
(b) Draw the dual network of the circuit shown in figure 5b.
6.(a) Using Norton’s theorem, find the current through the load impedance ZL as
shown in figure 6a.
(b) State and explain reciprocity theorem.
7.A series RLC circuit with R = 4 K
, L = 10 H and C = 100 µF has a constant
voltage of 60 V applied at t = 0. Find the current transient and the maximum
current, if the circuit is initially relaxed.
8.8. (a) Derive ABCD parameters from Z parameters.
(b) The Z parameters of a two port n/w are Z11 = 10
, Z22 = 20
, Z12 = Z21 =
5
.
i. Find the ABCD parameters.
ii. Find the equivalent T network. |