# EE 1152 ELECTRIC CIRCUITS LABORATORY

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 R-C 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 peak-to – 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 R-C 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.