R09 - December, 2010 - Regular Examinations - Set - 1.

B.Tech II Year - I Semester Examinations, December 2011
ELECTRICAL CIRCUITS
(COMMON TO EEE, ECE, ETM)
Time: 3 hours Max. Marks: 75
Answer any five questions
All questions carry equal marks
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1.a) Calculate the power absorbed by each component in the circuit shown in below Figure.1.
Figure.1
b) A series circuit with R= 2 ohms, L = 2 mH, and C = 500 micro-farads has a current which increases linearly from zero to 10 A in the interval 0 = t = 1 ms, remains at 10 A for
1 ms = t =2 ms, and decreases linearly from 10 A at t = 2 ms to zero at t = ms. Sketch VR, VL, Vc . [5 10]
2.a) Determine v1 and v2 in the circuit shown in below Figure.2.
Figure.2
b) Show by the application of Kirchhoff’s law that, for the potential divider shown in below Figure.3, 2012iRvvRR= . [8 7]
Figure.3

3.a) Determine the input impedance of the circuit shown in below Figure.4 at ? = 10 rad/s.
Figure.4
b) Find current I in the circuit shown in below Figure.5. [5 10]
Figure.5
4. In the circuit shown in below Figure.6 R = 2 ohns, L = 1 mH, and C = 0.4 µF.
a) Find the resonant frequency and the half-power frequencies.
b) Calculate the quality factor and bandwidth.
c) Determine the amplitude of the currents at resonant and half-power frequencies ?0, ?1, and ?2. [15]
Figure.6
5. For the network shown in below Figure.7, find Zab and Io. [15]
Figure.7

6. Draw a suitable tree and dual network for the Figure.8 shown below. Find V0 in the circuit shown below. [15]
Figure.8
7. With suitable example explain Millman’s and Compensation theorems for DC exitations.
For the circuit in below Figure.9, use the superposition theorem to find i and power in all resistances. [15]
Figure.9
8. With suitable examples explain Tellegen’s, Superposition theorems for AC circuits. Find the value of RL that will absorb the maximum average power (shown in Figure.10). Calculate that power. [15]
Figure.10
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