Question Paper: Electrical Circuit Analysis Question Paper - Jun 17 - Electrical And Electronics (Semester 3) - Jawaharlal Nehru Technological University (JNTUH)

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## Electrical Circuit Analysis - Jun 17

### Electrical And Electronics (Semester 3)

Total marks: 75

Total time: 3 Hours
INSTRUCTIONS

(1) Each question has 10 marks and may have a,b,c as sub questions.

(2) Part A is compulsory which % carries 25 marks. Answer all questions in Part A.Part B consists of 5 units . Answer any one full question from each unit.

(3) Draw neat diagrams wherever necessary.

**PART-A**

**1.a.**State ohm's law and mention its limitations.

**1.b.**Explain how voltage source with a source resistance can be converted into an equivalent current source.

**1.c.**Mention the disadvantages of low power factor.

**1.d.**In a series R-C circuit, R = 10 $\small \Omega$ and C = 25nF. A sinusoidal voltage of 50 mHz is applied and the maximum voltage across the capacitance is 2.5V. Find the maximum voltage across the series combination.

**1.e.**Define mutual inductance and self inductance.

**1.f.**Find the total inductance of the three series connected coupled coils shown in the figure 1.

**1.g.**Mention the properties of a tree in a graph.

**1.h.**Explain graphical method to draw dual network.

**1.i.**State superposition theorem and Reciprocity theorem.

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(3 marks)
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**1.j.**Give the proof of Tellegen's theorem.

**PART-B**

**2.a.**State Kirchoff's voltage and current laws.

**2.b.**Find 'I' in the circuit given in figure 2. Check the power balance condition.

**3.a.**Determine the node voltages and the current through the resistors using mesh method for the network given in figure.

**3.b.**Mention the difference between nodal analysis and mesh analysis.

**4.a.**A series R-L circuit, has resistance of 20$ \small \omega$ and inductance of 0.02H. If the net impedance of the given circuit is 40<$\small \phi \small \Omega$, find $\small \phi$ and the frequency of the circuit.

**4.b.**Define RMA value, Average value and Form factor.

**5.a.**A Voltage

*v(t)*= 200 sin wt is applied to a series RLC circuit where $R = 60\small \Omega$ , L = 0.18mH, and C = 20 \small \microF$ , Find :

a) The Power supplied by the source.

b) The reactive power supplied by the source.

c) The reactive power of the capacitor.

d) The reactive power of the inductor and

e) The power factor of the circuit.

**6.**Derive the equation for quality factor of series resonating circuit and parallel resonating circuit.

*OR*

**7.a.**Define quality factor and Bandwidth.

**7.b.**In the coupled circuit given in figure 4, find the input impedance as well as the net inductance when L1 = 0.2H, L2 = 0.5H coefficient of coupling (K) being 0.5.

**8.a.**Explain the concept of duality.

**8.b.**Define a fundamental Tie set and Cut set matrix. Five the procedure for obtaining the same with suitable examples.

**9.a.**The figure 5 represents a graph pf a network. Show the tree, twigs and links.

**9.b.**Convert the given current source to voltage source shown in figure 6.

**10.a.**State and explain Thevenin's and Norton's theorems.

**10.b.**Using Milliman's theorem find the current through Rl and voltage drop in the circuit given in figure 7.

**11.a.**State and explain Maximum power transfer theorem and compensation theorem.

**11.b.**Find the Norton's equivalent circuit across a-b for the network shown in figure 8.