JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II NETWORK THEORY Previous Question Paper (December - 2018 - R15)

Write the relationships between line and phase currents and line and phase voltages for a delta connected system.

What are the reasons for unbalance of phases in a 3-phase system?

Why current through a pure inductor does not change instantaneously?

A capacitor of capacitance C farads is connected in series with a resistor of R ohms and is switched across a constant voltage DC supply of V volts. After a time of t seconds, the current flowing is i amperes. Write the expression for voltage drop across the resistor at time t seconds? What is the expression for final value of capacitor voltage?

Give the properties of transfer function.

What are the necessary conditions for driving point function?

Write the conditions for symmetry and reciprocity with reference to y-parameters?

In a two port network, Y₁₁=0.3 S; Y₁₂=Y₂₁= -0.1 S; Y₂₂=0.2 S. Compute Z₁₁, Z₁₂, and Z₂₂.

What is the difference between Fourier integrals and Fourier transforms.

Obtain the Fourier transform of constant signal.

Explain two wattmeter methods for measurement of three phase power.

Each phase of a balanced star-connected load consists of R = 10 ohm and C = 10 µF connected in series. Calculate the line currents and total real and reactive powers when a symmetrical 415 V, 50 Hz, three-phase supply is applied to it.

Explain the advantages of polyphase system over single phase system.

A 3 phase, 4-wire, 415 V, AC system supplies a star-connected load in which Z_A = 10∠0°, Z_B = 15∠30°, and Z_C = 10∠-30° ohm. The phase sequence is ABC. Find currents and power absorbed.

Derive an expression for voltage across ‘R’ in a series R-C circuit excited by a unit step voltage. Assume zero initial conditions.

A series R-L circuit with R=100 ohms and L= 1 H has a sinusoidal voltage source 200 sin(500t + φ) applied at time when φ = 0. i) Find the expression for current ii) At what value of φ must the switch be closed so that the current directly enter steady state.

Derive an expression for voltage across capacitor in a series R-C circuit with sinusoidal excitation.

A series R-L circuit with initial current I₀ in the inductor is connected to a DC voltage V at t=0. Derive expression for the instantaneous current through the inductor for t > 0.

Obtain the pole-zero plot of the given function and obtain the time domain response I(s) = (s+1)(s+2)(s+4)/s^2.

Obtain the transfer function V₂(s)/V₁(s) of the network shown in figure 1 and find V₂(t) when V₁(t) = 10e^-t V.

A transfer function is given Y(s) = 10s / ((s+5+j15)(s+5-j15)). Find the time domain response.

Find transfer function of network shown in Figure 2.

Explain the analysis of prototype band-pass filter.

Design constant K band stop filters (both T and π sections) for the cutoff frequencies of 2 kHz and 6 kHz. The design impedance is 500 ohms.