RAJIV GANDHI COLLEGE OF ENGINEERING AND TECHNOLOGY

DEPARTMENT OF BIO-MEDICAL ENGINEERING

SUBJECT NAME: ELECTRICAL CIRCUIT ANALYSISYEAR: III

SUBJECT CODE: BM T32 SEMESTER: V

PART-A 2 MARKS

UNIT-I

1. State Kirchhoff’s laws;

2. What is power factor?

3. State 2 examples for active and passive elements?

4. What is real power?

5. What is reactive power?

6. What is complex power?

7. A series combination of 10 ohm resistor and 50 my inductor is connected to a 220 V, 50 Hz supply. Find the current drawn by the circuit?

8. State the units of VOLTAGE, CURRENT, and POWER & RESISTANCE?

9. State KCL?

10. State KVL?

UNIT-II

1. State superposition theory?

2. State reciprocity theory?

3.. Determine the significance of maximum power transfer theory?

4. State Thevenin’s theory?

5. State Norton’s theory?

6. What is compensation theory?

7. State Millman’s theory?

8. State Tellegen’s theory?

9. State star to delta transformation?

10. State delta to star transformation?

UNIT -III

1. What is bandwidth & selectivity?

2. What is Q-factor?

3. What is Resonance?

4. Define resonant frequency?

5. State Faraday’s law of electromagnetic induction?

6. What is coefficient of coupling?

7. State two watt meter method?

8. What are line & plane voltages?

9. What are line and plane currents?

10. What is lot convention?

UNIT –IV

1. Define the time constant of RL circuit?

2. Write the time constant of series RL&RC circuits?

3. Define the time constant of RLC circuits?

4. What is meant by Transient state?

5. What is transient response?

6. State any 2 initial conditions in element?

7. What are step excitations?

8. What are sinusoidal excitations?

9. What is different equations approach?

10. What is Laplace transform method?

UNIT – V

1. Define the term POLES & ZEROS.

2. What is meant by complex frequency?

3. What is a two port network?

4. What is driving point impedance?

5. What is driving point admittance?

6. What are band pass &band reject filters?

7. What are low pass& high pass filters?

8. What are ABCD parameters?

9. Draw a 2 port network in terms of hybrid parameters?

10. What are Z & X parameters?

PART-B 11 MARKS

UNIT – I

  1. In the ckt,given, determine the total impedance ,current I, phase angle theta and the voltage across each element

  1. Find the voltage across the terminal Aand B of the network shown in figure

  1. Calculate the current supplied by the battery in the given circuit

  1. Calculate the total resistance and battery current in the given circuit.

  1. Determine the value of R if the power dissipated in 10 ohm resistor is 40 w for the circuit
  2. D
  1. The current in 6 ohm resistor of the network shown, determine the current in all other resistor and the voltage v across the network
  1. If the total power dissipated in the circuit shown in 18 watts, find the value of R and current through it
  1. Calculate the equivalent resistance of the following combination of resistor and the source current

  1. Determine the equivalent resistance between A and B.

  1. Find The Current I In The Figure

UNIT – II

  1. Obtain the thevenin’s equivalent circuit for the circuit shown in figure below with respect to the terminals AB.
  1. Using Superposition theorem, find the current through 15Ω resistor of the circuit given below.
  1. State and explain Millman’s theorem and determine the node voltages in the figure.
  1. Find the current flow through 8Ω resistor using mesh analysis of the circuit below.
  1. Find the voltages Vaand Vbin the network shown in figure below.

UNIT – III

  1. a)What are the advantages of three phase system?

b)A series RLC circuit with R=10ohm, L = 1 mH and C = 1000 picofarads connected across sinusoidal source of 20v with variable frequency.

  1. Compute the resonant frequency of the circuit
  2. Find the Q factor of the circuit at the resonant frequency
  3. Determine the half power frequencies
  1. A) A balanced star connected load of 8+j6 ohm/phase is connected to a three phase, 230v, 50 c/s supply. Find the line current, power factor, power, reactive volt amperes and total volt amperes.

B) Explain the concept of self inductance and mutual inductance in coupled circuits.

  1. A) Derive the resonance frequency of a series RLC circuit

B) A series RLC circuit consists of R = 100ohm, L=100mH and C=10nF. The applied voltage across the circuit is 100 V. find the resonance frequency, Quality factor and bandwith.

  1. A) Determine the quality factor of a coil for the series circuit consisting of R = 10ohm,L = 0.1H and C = 10uf

B) A balanced load consists of three coils with each coil having a resistance of 10ohm and an inductive reactance of 15ohm. The load is connected as star to a 420V, 50Hz three phase supply, find

i) Line currents

ii) Power factor

  1. Explain the concepts of series resonance circuit with a neat diagram. Derive an expression for its resonant frequency and bandwith
  2. The wattmeter in line A and B of 173.2V ABC system read -301 and +1327 watts respectively. Find the impedances of the balanced star connected load.

UNIT IV

  1. Using classical method solve the differential equation

d2y(t) + 5 dy(t) + 6 y(t) = dx(t) + 4x(t)

dt2 dt dt

if input x(t) = e-tu(t). Find

(i)Natural response for initial conditions

y(0+) =- 3 and dy(0+) = 0

dt

(ii)Forced response

(iii)Total response

  1. Solve the differential equation using laplace transform

d2y(t) + 7dy(t) + 12 y(t) = e-t

dt2 dt

where y(0-) = 3 and dy(0+) = 0

dt

  1. A series RLC circuit consisting of a resistance R = 15Ω, an inductance L = 0.05H and a capacitance C = 20µF is connected with a 100V constant source in series. Determine the current transient.
  1. Obtain the current transient for the circuit shown below
  1. A series RC circuit with R = 5kΩ and C = 20µF has constant voltage source of 100 V applied at t = 0, there is no initial charge on the capacitor. Obtain the current I and charge q for t>0.
  1. Derive the expression for the complete solution of current response of RC series circuit with an excitation of Vcos (ωt + ɸ).
  1. A series RLC circuit with R = 3KΩ, L = 10H and C= 200µF has a constant voltage V= 50 V applied at t = 0. Find the current transient and the maximum value of the current if the capacitor has no initial charge.
  1. A series RLC circuit has R = 20Ω and C = 100µF. A voltage V = 200 sin 314t is applied at t = 2.14 sec. Obtain an expression for i. Also, find the value of current after time 1 msec from switching instant.
  1. Two coils have a coupling coefficient K = 0.85 and coil 1 has 250 turns. The current in coil 1 is 2A and the total flux is 0.3mwb. When the current i1 is reduced linearly to zero in 2 milliseconds, the voltage induced in coil 2 is 63.75volts. Find L1, L2, M and N2.
  1. The wattmeters in line A and B of a 120 volts, ABC system read 1500 watts and 500 watts respectively. Find the impedance of the balanced delta connected load.
  1. A series RC lowpass filter with a cutoff frequency of 5 kHz is needed. Using R = 10 KΩ, compute (a) C (b) |H(jω)| at 25 kHz (c) H(jω) at 25 kHz
  1. The following direct – current measurement were made on the two port network.

Port 1 open circuited Port 1 short circuited

V1 = 1 mV I1 = -1 µA

V2 = 10 V I2 = 40 µA

I2 = 100 µA V2 = 5 V

Calculate the h – parameters of the network.

13. A.) A series Rc high pass filter has C=10µF. Compute the cutoff frequency for the following values of R (a) 1000Ω (b) 5000Ω (c) 30KΩ

B.) Design the RLC band reject filter for the following specifications.

f0 = 4KHz; C = 500nf; Q = 5.

UNIT V

  1. With relevant circuit diagram and derivations, briefly describe the operation of RC low pass and high pass filters.
  1. Compute the Z – parameter of the two port network shown below.
  1. State the relationship between Z-parameters and Y – parameters.
  1. Find the h parameter for the network shown below.
  1. Find the Z parameter and Y parameter of the network shown below
  1. Obtain the driving point admittance of the network shown in figure.
  1. A. Explain the limitations of poles and zeros location in transfer function of network function.

B. find pole – zero plot of the transfer function.

s2+4s+13

H(s) =

(s+1) (s2+6s+10)