# Past Papers Circuit Analysis

By Prof. Fazal Rehman Shamil

## Guess Paper 1: Circuit Analysis Fall – 2020 Past Papers

University Name – Confidential

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1. Write short notes of any TWO of the following?
(a) Need for circuit analysis (b) Phasor diagram (c) Superposition theorem (d) KVL and KCL

Q.2. State Ohm’s Law. Discuss its scope and range of validity.

Q.3. Explain the Thevenin theorem.

Q.4. Consider the circuit shown in Figure 1.
(i) Calculate the current through each resistor.
(ii)The power dissipated as heat in each resistor.

Q.5. Find the current in the resistors of Figure 2.

Q.6. Explain the phenomenon of mutual induction. What are the practical applications of the inductor?

Q.7. (a) What is a capacitor? Give some common applications of capacitors.
(b) A capacitor with air between its plates has a capacitance of 3. What is the capacitance when wax of dielectric constant 2.8 is between the plates?

Q.8. A purely capacitive circuit is energized by sinusoidal emf source.
Give the answer of the following parts :
(a) Draw the circuit diagram.
(b) Write the equations for voltage and current in the circuit.
(c) Draw the V-t and I-t characteristic curves.
(d) Discuss the phase relationship between V and I.

## Guess Paper 2: Circuit Analysis Spring – 2020 Past Papers

University Name – Confidential

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1. Explain the Thevenin theorem and Norton theorem.

Q.2. What is a complex network? State and explain with diagrams Kirchhoff’s laws.

Q.3. Explain the superposition theorem.
Q.4. (a). Obtain expressions for the equivalent capacitance of capacitors when connected in (a) series and (b) parallel.
(b).Two capacitors C1 = 6µ F and C2 = 12µF are connected in series to a voltage source of 1000 V. Calculate the (a) total capacitance, (b) the charge on each capacitor and (c) the potential drop across each capacitor.

Q.5. (a). What is the transformer? Give it the principle of working and construction..
(b).The turns-ratio of a step-up transformer is 50. A current of 20 A is passed through its primary coil at 220 V. Obtain the value of the current and voltage in the secondary coil assuming the transformer to the ideal one.
Q.6. A purely resistive circuit is energized by sinusoidal emf source.
Give the answer of the following parts :
(a) Draw the circuit diagram.
(b) Write the equations for voltage and current in the circuit.
(c) Draw the V-t and I-t characteristic curves.
(d) Discuss the phase relationship between V and I.

Q.7. A sinusoidal A.C. voltage V(t) of frequency ω rad/sec is applied to an RLC series combination.
(a) Draw the circuit diagram and the phasor diagram.
(b) Obtain expressions for the impedance of the circuit, current in the circuit, phase angle between current and voltage, and the power dissipated in the circuit.

Q.8. A series LCR circuit is excited by a sinusoidal signal. Obtain its frequency response. Show that the circuit has a resonance frequency

## Guess Paper 3: Circuit Analysis Spring – 2019 Past Papers

University Name – Confidential

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q1. Briefly define each of the following:
a. Voltage Source
b. Current Source
c. Henry
d. Watt
e. Inductance
f. Low Pass Filter
g. Frequency

Q2. What is first-order circuit also explain R-C circuit and R-L circuit with circuit diagram?

Q3. Derive the equation for the voltage across the capacitor in the R-C circuit.

Q4. Explain the following:
a. Unit Step function.
b. Unit Impulse function.
c. Unit ramp function.
Q5. What is a two-port network? Derive the expression for the conversion between Z and Y parameters for a two-port network.

Q6. Define the mutual inductance of two circuits. Explain the analysis of circuits containing coupled coils using dot rules.

Q7. What is a power measurement by two watts method? Explain

Q8. Write short notes on any TWO.
a. Complex Frequency
b. Application of Fourier transform

## Guess Paper 4: Circuit Analysis Fall – 2019 Past Papers

University Name – Confidential

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1 Fill in the blanks [14 Marks]
a. The unit of Current is _¬¬¬¬¬¬______.
b. The unit of Power is _¬¬¬¬¬¬______.
c. The Voltage Divider Technique is used in _¬¬¬¬¬¬______ circuit.
d. The capacitor is that Element, having the ability to pass the AC signal and store _____ signal.
e. A Norton Equivalent Circuit Consist of ………………………………
f. The opposition of flow of current is as known as ………………………………
g. The Unit of Resistance is …………………………………………………….

Q.2. (a) Define Resistance. Derive the General Formula to find the total Equivalent resistance when resistors are connected in parallel.
(b) Define Current divider rule/Techniques and also derive its general formula. (14)

Q.3. (a) Write down the Statement of Norton Theorem/Principle.
(b) Explain the Maximum Power Transfer Theorem in detail. (6+8)

Q.4. (a) Briefly Discuss the Fundamentals of Lumped Networks.
(b) Find the value of Ia and Ib using the node voltage method. (6+8)

Q.5 (a) Explain the Functions of Different Types of Capacitors.
(b)Explain the function of inductors in the DC & AC Circuits. (6+8)

Q.6 (a) Define Band & Stop Filters and also discuss the Filter Application.
(b) Discuss the response of the Energy Storage Elements to DC Sources. (6+8)

Q.7 (a) Discuss the Concept of Time Domain versus the frequency Domain Analysis of Circuits.
(b)Find out the total impedance of the below-given circuit using a frequency of 500 Hz.
(6+8)

Q.8. Write short notes on any TWO of the following.
(a) Inductor Types (07)
(b) Statement of KVL and KCL (07)
(c) Superposition Theorem (07)

## Guess Paper 5: Circuit Analysis Fall – 2018 Past Papers

University Name – Confidential

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1 Fill in the blanks [14 Marks]
a. The unit of voltage is _¬¬¬¬¬¬______.
b. The unit of inductance is _¬¬¬¬¬¬______.
c. The Current Divider Technique is used in _¬¬¬¬¬¬______ circuit.
d. One eV (electron Volt) is equal to………………………………………………………..
e. A Thevenin Equivalent Circuit Consist of ………………………………
f. The primary function of Oscillator is ………………………………
g. The Unit of Resistivity is …………………………………………………….

Q.2. (a) Write down the Kirchhoff’s Current Law both statements.
(b) Define Voltage divider rule/Techniques and also derive its general formula. (14)

Q.3. (a) Write down the Statement of Thevenin Theorem/Principle.
(b) Explain the Maximum Power Transfer Theorem in detail. (6+8)

Q.4. (a) Write down the general Statement of Superposition Theorems.
(b) Using the superposition theorems, determine the voltage drop and current across the resistor 3.3K as shown in the figure below. (6+8)

Q.5 (a). Explain the function of inductors in the DC & AC Circuits.
(b) Determine the amplitude of the electric current in the circuit and a phase difference between the voltage and the current. (6+8)

Q.6 (a) Define Band & Stop Filters and also discuss the Filter Application.
(b) Discuss the response of the Energy Storage Elements to DC Sources. (6+8)

Q.7 (a) Discuss the Concept of Time Domain versus the frequency Domain Analysis of Circuits.
(b) Calculate the impedance of the parallel RLC circuit and the current drawn from the supply.
(6+8)

Q.8. Write short notes on any TWO of the following.
(a) Inductor Types (07)
(b) Capacitor Types (07)
(c) Differentiation b/w Active and Passive Filter (07) Prof.Fazal Rehman Shamil (Available for Professional Discussions)
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