The document describes an experiment to obtain the voltage-current (V-I) characteristics of a fluorescent lamp. The apparatus required includes a voltmeter, ammeter, fluorescent lamp, choke, starter, and auto transformer. The procedure involves connecting the circuit and increasing the auto transformer output voltage slowly until the lamp lights up, recording meter readings at different voltages, then decreasing the voltage until the lamp turns off. Graphs of lamp voltage vs current and choke voltage vs current will be plotted from the tabular readings. Precautions include making tight connections, using proper meter ranges, and avoiding parallax error when taking readings.

1. Fluorescent Lamp
Aim: To obtain the V-I characteristics of a Fluorescent Lamp.
Apparatus required:
S.No Name of the
equipment
Range/
Specification
Type Quantity
1 Voltmeter (0-300) V MI 3
2 Ammeter (0-1) A MI 1
3 Fluorescent lamp 36W, Discharge 1
4 Choke 230V, 40W Core type 1
5 Starter 20-65 W,
1-ɸ, (230-250)V,
Glow-Type 1
6 1- Phase Auto
Transformer
I/P: 1-ɸ, 230V
O/P: (0-270)V,10A
Core type 1
7 Connecting wires 1.5 Sq.mm Copper Required
Procedure:
1. Connect the circuit as per circuit diagram.
2. With the autotransformer at zero output position, close the DPST switch.
3. Increase the output voltage of the autotransformer in steps until the lamp lights up.
Note down the meter readings.
4. When the lamp starts to glow, increase the autotransformer output voltage until the
rated voltage of the lamp is obtained i.e.230V, enter the readings of the meters in
Tabular column.
5. Decrease the supply voltage in steps until the lamp extinguishes. At each step record
the meter readings.
Circuit Diagram:

3. Tabular column:
S No VS
(Volts)
IL
(Amps)
V Choke
(Volts)
V Lamp
(Volts)
Lamp
condition
Incr Decr Incr Decr Incr Decr Incr Decr Incr Decr
Vs = Supply Voltage, VL = Voltage across the lamp
VC = Voltage across the choke, IL = Current through the lamp
Graph : Plot the graph (VL vs IL) & (VC vs IL).
Precautions:
1. All the connections should be tight
2. Use proper ranges of the meters.
3. Take the readings without parallax error.
3. All the connections should be tight.
4. Increase the output voltage of the auto transformer very slowly while starter / lamp
is blinking.
Result: