Experiment No - 10 Measurement of current and voltage in electrical circuits to Kirchhoff’s Law verify

Measurement of current and voltage in electrical circuits to Kirchhoff’s Law verify

Objectives       :  At the end of this exercise you shall be able to

• verify the Kirchhoff's Current Law with three branch circuit

• verify the Kirchhoff's Voltage Law with one voltage source.

Requirements

Materials/Components

• SPST Toggle Switch/1A - 1 No
• Resistor, 1k:/1W - 3 Nos
• Resistor, 2.2k:1W - 1 No
• Resistor, 3.3k:/1W - 1 No
• Rosin cored solder - 1 m
• Soldering flux - 1 Box
• Hook-up wires - 2 m
• Patch Cords - 10 Nos
• Lug Board - 1 No

Tools/Equipment/Instruments

• Trainees Tool Kit - 1 Set
• Soldering Iron, 230V/25 watts - 1 No
• Milli-Ammeter, 0-10m.A, DC - 3 Nos
• Milli-Ammeter, 0-5m.A, DC - 1 No
• Multi meter with probes - 1 No
• Regulated DC power supply 0-30V/1A - 1 No

PROCEDURE

TASK 1: Verification of Kirchhoff's Current Law

1. Check physical and electrical condition of the given ammeter, meter prods, patch cords, toggle switch soldered on the lug board.
2. Make the connections on the Lug board as per the circuit diagram. (Fig 1)
3. With the SPST in OFF position, set the output of Power Supply to 12 volts. 
   
   
   
4. Switch ON the SPST switch. Measure and record currents, IT, IB1, IB2, and IB3 in Table-1.
5. Switch OFF SPST and PSU.
6. Write Kirchhoff's current equations at Nodes P and Q. Verify the equation using measured current values.
7. Get the work checked by the Instructor.

TASK 2: Verification of Kirchhoff's voltage  Law

1. Check physical and electrical condition of the given meter probes, patch cords, toggle switch soldered on the lug board. 
2. Measure and record the values of Resistor R1, R2 and R3 in the Table.
3. Make the connection on the Lug board as per the circuit diagram. (Fig 2)
4. With the SPST in OFF position, set the output of Power Supply to 12 volts. 
   
   
   
5. Mark the polarity of the voltage drops across resistors R1, R2 and R3.
6. Switch ON the SPST switch.
7. Following the voltage polarities marked across the resistors, measure and record the voltage drop across R1, R2 and R3 in Table.
8. Switch OFF SPST and Regulated power supply.
9. Write Kirchhoff's loop equations for the closed paths a-c-d-b-a, a-e-f-b-a and c-e-f-d-a. Substitute the voltage readings recorded in Table in the equations for verification.
10. Verify the equation using measured voltage values.
11. Get the work checked by the Instructor.

Loop:- a-c-d-b-a:

                       +V1 +V2 - VT = 0

                       +V1 +V2 = VT

           Loop:- a-c-e-f-d-b-a: 

                        +V1 +V3 - VT = 0 

                        +V1 +V3 = VT

Loop:- c-e-f-d-e:

                       +V3 - V2 = 0 V3 = V2