Instrument Specification

1. Variac ( Input 110/220V, Output 0-300V) used to input a varying voltage to the circuit
2. 3 Voltmeters, each having a scale of 0-300 V to measure the voltage across the circuit, across the lamp and across the choke
3. One Ammeter (0-1A) to measure the current in the circuit
4. Wttmeter 0-300V,2A

• Current coil connected in series, and pressure coil across the circuit
• Two current coils are themselves current in circuit such that the rated current is 1A
• The pressure coil terminals corresponding to 250V are used here
• Wattmeter Reading has to be multiplied by 2 for this combination of 1A, 250V

• Vary the input voltage by the variac from zero and note the voltage at which fluorescent lamp strikes.
• Note down the readings of the voltmeters, ammeter, and the wattmeter from striking voltage upto 230V in steps of 10V.
• Wattmeter reading should be taken twice, once when switch in position Ch and another switch in position Tot



Note: For the position Ch of the switch, wattmeter indicates the power consumed by the choke For the switch in position Tot, wattmeter indicates the total power consumed by the circuit

• Connect the meters as per circuit diagram of RUN 2.
• There is only one voltmeter used in this case for noting down the input voltage.

• Vary the input voltage by the variac from zero and note the voltage at which fluorescent lamp strikes.
• Note down the readings of the voltmeter, ammeter, and the wattmeter at 230V.