EXPERIMENT NO: 4 AIM: To calculate and verify 'ABCD' parameters of two-port network APPARATUS REQUIRED: Power Supply, Bread Board, Five resistances, Connecting Leads, Voltmeter, and Ammeter. BRIEF THEORY: ABCD parameters are widely used in analysis of power transmission engineering where they are termed as "Circuit Parameters". ABCD parameters are also known as "Transmission Parameters". In these parameters, the voltage & current at the sending end terminals can be expressed in terms of voltage & current at the receiving end. Thus, Here "A" is called reverse voltage ratio, "B" is called transfer impedance "C" is called transfer admittance & "D" is called reverse current ratio. CIRCUIT DIAGRAM: I1 V1 V = AV 2+ B (-1) I = CV + D (-1) R1 R4 R2 R5 R3 12 V2 PROCEDURE: a) Connect the circuit as shown in fig. & switch 'ON' the experimental board. b) First open the O/P terminal & supply 5V to I/P terminal. Measure O/P voltage & I/P PROCEDURE: a) Connect the circuit as shown in fig. & switch 'ON' the experimental board. b) First open the O/P terminal & supply 5V to I/P terminal. Measure O/P voltage & I/P current c) Secondly, short the O/P terminal & supply 5V to I/P terminal. Measure I/P & O/P current using multi-meter. d) Calculate the A, B, C, & D parameters using the Eq. (1) & (2). e) Switch off the supply after taking the readings. OBSERVATION TABLE: S.No When O/P is open ckt V V I SAMPLE CALCULATION: (1)When O/P is open circuited i.e. I = 0 A = V/V C = 1/V (2) When O/P is short circuited i.e. V = 0 VI When O/P is short ckt 1 I B = -V/1 RESULT/CONCLUSION: The ABCD-parameters of the two-port network has been calculated and verified. DISCUSSION: ABCD parameters are transmission parameters. PRECAUTIONS: a) Make the connections according to the circuit diagram. Power supply should be switched off. D=-11/1 b) Connections should be tight. c) Note the readings carefully.