JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech II Year NETWORK THEORY Previous Question Paper (April/May - 2018 - R16)

Define the terms (i) planar graph (ii) non planar graph.

Two coupled coils with N1=200 and N2=600 turns have a K=0.8. With coil 1 opened and current of 10 A in coil 2, the flux in coil 2 is 0.38 mWb. Find L1, L2 and M.

Obtain the relationship between phase voltages and line voltages in three phase balanced star system.

Three identical impedances (3+j4) ohms are connected in a delta connection to a three phase, three wire 230 V ABC system. Find the line currents.

Find Laplace transform of the rectangular signal with an amplitude of 1.0 units and a time period of T sec.

Voltage across a capacitor cannot change instantaneously. Justify.

A two port network has the following Z-parameters. Find h parameters.

Write the necessary conditions for driving point and transfer function.

Write the significance of cutoff frequency of a filter.

A series low pass filter with a cutoff frequency 6 kHz is needed. Using R= 12 kΩ, calculate (i) C (ii) |H(jω)| at 25 kHz and (iii) angle of H(jω) at 25 kHz.

Obtain the Thevenin's equivalent circuit at terminals AB of the coupled circuit shown in Figure 1.

Write the procedure to draw the dual network of RLC series circuit and construct its dual network.

For the circuit shown in Figure 2 find the maximum power delivered to the load.

For the graph shown in Figure 3 write the (i) incidence matrix and (ii) express branch voltages in terms of node voltages.

A balanced star load with impedances of (9+j7) ohms to a three phase four wire 480 V ACB system. Find the line currents and total power.

With a neat circuit diagram, explain measurement of power with two wattmeter method.

Two wattmeters in line A and B of a 230 V, RYB system read 1500 W and 500 W respectively. Find the impedance of the balanced delta connected load.

A three phase three wire 220 V, ABC system supplies a delta connected load where ZAB=(10-j10) ohm, ZBC=(12+J8) ohm and ZCA= 23 ohm. Find the current and the readings of wattmeters in lines A and C.

A series RLC series circuit with R=5 ohm, L=0.1 H and C=500 micro F has a constant voltage V=25 V applied at t=0. Find the resulting current.

Obtain the response of an RL series circuit when it is excited with ramp input.

The switch is closed at t=0 connecting a voltage source V=V sinωt to a series RL series circuit. Derive an expression for i(t).

From the fundamentals obtain the step response of a series RC circuit.

Find Z-parameters of T-network with series branches of 4 ohm and a shunt branch of 8 ohm. Derive the necessary equations.

Obtain Y parameters in terms of ABCD parameter of a two port network.

Obtain input impedance, voltage and current transfer functions in terms of ABCD parameters of a typical two port network.

The following direct current measurement were made on the two port network: Port 1 open (V1= 2 mV, I2= 40 µA), Port 1 short circuited (I1=-1 µA, V2=5 V, I2= 100 µA). Calculate h parameters of network.

Draw the circuit diagram of series RL circuit that acts as a high pass filter. (i) Write an expression for the circuit transfer function (ii) Find the value of R and L that will yield a high pass filter with a cutoff frequency of 10 kHz.

Explain in detail about constant K and m derived filters.

With a neat sketch draw the magnitude response of (i) low pass and (ii) high pass filters. Justify your answer.

Write short notes on band pass and RC filters.