DEPARTMENT OF ELECTRICAL ENGINEERING B.TECH.
1ST YEAR (COMMON TO ALL BRANCHES) LAB MANUAL
UNITED INSTITUTE OF TECHNOLOGY
BASIC ELECTRICAL ENGINEERING LAB MANUAL
Experiment No: 6
PARAMETERS OF AC SINGLE PHASE SERIES RLC CIRCUIT
1.1 Objective 1.2 Apparatus required 1.3 Theory 1.4 Connection Diagram 1.5 Observation table 1.6
Calculation 1.7 Result 1.8 Discussion 1.9 Precautions 1.10 Pre-Requisites 1.11 Post- Requisites
1.1 OBJECTIVE: DETERMINATION OF PARAMETER OF AC SINGLE PHASE RLC CIRCUIT
1.2 APPARATUS REQIRED: (a) Single phase Transformer – 01
(b) Unknown Inductances (L1, L2 & L3) -03
(c) Unknown Capacitances (C1,C2,C3 & C4) -04
(d) Unknown Resistance (R1,R2 & R3) -03
(e) Multimeter
(f) Patch Cords
1.3 THEORY: In the present circuit resistance R ,inductance L and capacitance C are connected in
series across a voltage Vs. Thus the current in all the elements of the circuit is the same, where as voltage
across each element would be different. Resultant applied voltage Vs is the phasor sum of all the voltages
across these elements. In such a series circuit, following basic relation hold good.
Voltage across the Resistance Vr =IR
Voltage across the Inductances VL = IXL
Voltage across the Capacitances Vc = IXc
Voltage applied across the circuit V = IZ
Power drawn by the circuit P = VIcosф
Power factor of the circuit cosф = P/VI
Where,
XL =Inductive resistance = ῳL = 2πfL
Xc = Capacitance Reactance = 1/ῳC = 1/ 2πfC
Z = Inductance of the circuit =
I = Current flowing in the circuit =
The power factor Cos ф =
The power factor of such a circuit is lagging when ῳL˃ (1/ ῳC) and is leading when ῳL ˂ (1/ ῳC).
Hence, by measuring the voltage across various elements,applied voltage, current flowing in the circuit
and the power consumed by the circuit and the power cosumed by the circuit, all the parameters circuit
can be calculated.
BEE-151/251 BASIC ELECTRICAL ENGINEERING LAB
DEPARTMENT OF ELECTRICAL ENGINEERING B.TECH. 1ST YEAR (COMMON TO ALL BRANCHES) LAB MANUAL
1.4 CONNECTION DIAGRAM:
1.5 OBSERVATION TABLE:
SL. NO. Vs (Volts) I (Amp) Vr (volts) VL (Volts) Vc (Volts)
1.
2.
3.
4.
5.
1.6 CALCULATIONS:
SL. NO. R=Vr/I XL =VI/I L=(XL/2πf)103 Xc=Vc/I C=1/(2πfXc)106
(ῼ) (ῼ) (mH) (ῼ) (µF)
1.
2.
3.
4.
5.
1.7 RESULT:
1.8 DISCUSSION:
1.9 PRECAUTIONS:
1.All connection should be tight & right.
2. Do not touch live wire.
3.Take reading very carefully.
1.10 PRE-REQUISITES:
Q1. What is inductive and capacitive reactance?
Q2. Define power factor.
1.11 POST-REQUISITES:
Q1. What will be the behavior of the circuit based on the values of XL and XC?
Q2. On what basis it is decided that the power factor will be leading or lagging?
BEE-151/251 BASIC ELECTRICAL ENGINEERING LAB
