EE 1152 ELECTRIC CIRCUITS LABORATORY 0 0 3 100
OBJECTIVE
To impart hands on experience in verification of circuit laws and theorems, measurement of circuit parameters, study of circuit characteristics and simulation of time response.
1. Verification of Kirchoff's voltage and current laws, Thevenin's and Norton's Theorems.
1. Study of oscilloscope and measurement of sinusoidal voltage, frequency and power factor.
1. Measurement of time constant of series RC electric circuits. 2. Frequency response of RC and RL circuits. 3. Resonant frequency and frequency response of a series RLC circuit.
6. Study of the effect of Q on frequency response and bandwidth of series and
parallel resonant circuits.
7. Study of low pass and high pass filters.
1. Measurement of real power, reactive power, power factor and impedance of RC, RL and RLC circuits using voltmeters and ammeters.
1. Power measurement in a three phase circuit by two Wattmeters. 2. Study of first and second order circuit transients by digital simulation.
* *
P = 45 Total = 45
*REFERENCE BOOK*
1. Paul B.Zbar, Gordon Rockmaker and David J.Bates, 'Basic Electricity', A text – Lab Manual, McGraw Hill, Seventh Edition  2001.
Detailed Syllabus
*1. **Verification of Kirchoff's voltage and current laws, Thevenin's and Norton's*
* Theorems*
* *
*Aim*
To verify Kirchchoff's voltage and current laws, Thevenin's and Norton's Theorems.
* Exercises*
1. Verify the Kirchoff's voltage and current law in a series circuit and in a circuit with series and parallel combination.
2(a) Determine the Thevenin equivalent voltage VTH and resistance RTHof a
DC circuit with a single voltage source.
(b) Verify experimentally the values of VTH and RTH in solving a series –
parallel circuit.
3. Determine the values of Norton's constant – current source IN and Norton's current – source resistance RN in a DC circuit containing one or two voltage sources.
*2. ** Study of Oscilloscope and Measurement of sinusoidal voltage, frequency and *
* power factor*
* Aim*
To study the dual trace oscilloscope controls and to AC voltage values, time and frequency of A.C voltage with the oscilloscope.
*Exercises*
1. Learn the dual trace oscilloscope controls, safety precautions, probe compensation and the procedure to measure A.C. voltage and phase angle measurement.
2. Measure peakto – peak A.C. voltage waveform using the oscilloscope.
3. Measure time for one cycle of an A.C signal and the corresponding frequency using the oscilloscope.
*4. *Measure the phase angle difference between two A.C signals using dual trace oscilloscope.**
* *
*3. Measurement of time constant of series RC electric circuits*
Aim
To determine experimentally the time taken by a capacitor to charge and discharge through a resistance.
* Exercises*
a. Determine experimentally the time it takes a capacitor to charge through a resistor and obtain a plot between voltage across capacitor and time.
b. Determine experimentally the time it takes a capacitor discharge through a resistor and obtain a plot between voltage across capacitor and time.
c. Experimentally verify that the current and voltage in a capacitive circuit are out of phase using dual trace oscilloscope.
1. *Frequency response of RC and RL circuits*
*Aim*
1. To study the effect on impedance and current of a change in frequency in a series RL circuit.
2. To study the effect on impedance and current of a change in frequency in a series RC circuit.
Exercises
1. Conduct suitable experiment and draw the following graphs for an RL circuit.
a. Impedance Vs frequency
b. Current Vs frequency
c. XL Vs f
2. Conduct suitable experiment with a RC circuit and draw the following graphs.
i. Xc Vs f
ii. Z Vs f
iii. I Vs f
1. *Resonant frequency and frequency response of a series R L C circuit*
*Aim*
1. To determine experimentally the resonant frequency fR of a series RLC circuit.
2. To verify that the resonant frequency of a series RLC circuit is given by the formula
fR = 1 / 2pv LC.
3. To develop experimentally the frequency – response curve of a series RLC circuit
Exercises
1. Draw the frequency response curve of a RLC circuit (VLVs f, V C Vs f)
2. Experimentally show the following
a. Resonant frequency fr = 1 / 2p vLC
b. The impedance at resonance Z = R
* *
1. *Study of the effect of Q on frequency response and bandwidth of series and parallel resonant circuits*
* *
*Aim*
To measure the effect of circuit Q on frequency response and on bandwidth at the half – power points.
* Exercises*
1. Experimentally study the effect of Q on frequency response and bandwidth of RLC resonant circuit and obtain the following for three values of Q.
i. I Vs frequency
ii. Half power points
iii. Bandwidth
iv. Ve Vs f
v. VL Vs f
2. Experimentally determine the resonant frequency in a parallel resonant circuit. Draw current versus frequency in parallel resonant circuit.
1. *Study of Low Pass and High Pass Filters*
*Aim*
To determine experimentally the frequency response of a low and high pass filters.
*Exercises*
1. Determine the frequency response of passive low pass (RL) and high pass (RC) filter circuits.
1. Determine the frequency response of active low pass and high pass filter circuits.
* *
1. *Measurement of real power, reactive power, power factor and impedance of RC, RL and RLC circuits using voltmeters and ammeters.*
* *
Aim
To measure real power, reactive power, apparent power, power factor and impedance in A.C circuits using ammeters and three voltmeters.
*Exercises*
1. Experimentally determine the power factor, real power, reactive power, apparent power and impedance in a RL series circuit using voltmeter and ammeter. Draw the phasor diagram using the measurements.
2. Experimentally determine the power factor, real power, reactive power, apparent power and impedance in a RC circuit. Draw the phasor diagram using the measurements.
3. Experimentally determine the power factor, real power, reactive power, apparent power and impedance in a RLC series circuit using voltmeters and ammeters. Draw the phasor diagram using the measurements.
*9. Power Measurement in a three phase circuit by two Wattmeters*
* Aim*
To measure power in a three phase circuit by two wattmeter method.
*Exercises*
1. Measure the real and reactive power input and power factor to a three phase induction motor at different load condition using two watt meters
*10.* *Study of first and second order circuit transients by digital simulation*
* *
Aim
To study the first and second order circuit transients by digital simulation.
*Exercises*
1. Obtain the response for the following cases using MATLAB software or any other equivalent.
a. Source free or zero input response of RL and RC circuit.
b. D.C or step response of RL and RC circuits using available software.
c. Obtain the source free and step response of RLC circuit using available softwares.
