Characteristic Curve of a Filament Lamp

A circuit was set up as shown in the diagram. The bulb used was marked '24W 12V'

The potential difference across the bulb was varied from 0V to 12V and voltmeter and ammeter readings and observations were recorded in a table.

Potential Difference / V	Current /A	Observations
0.0	0.00	Filament does not glow at all (Bulb feels cold)
0.2	0.21
0.4	0.40
0.6	0.51
0.8	0.58
1.0	0.61	Faint glow can be seen
2.0	0.82	Filament glows a dim red (bulb feels warm)
3.0	0.95	Filament bright red (bulb is hot)
4.0	1.12	Filament orange
5.0	1.28	Filament brilliant orange
6.0	1.44	Filament even brighter - now yellow (bulb is very hot to touch)
7.0	1.53	Filament yellow/white
8.0	1.63
9.0	1.74	Filament bright white light
10.0	1.85
11.0	1.94
12.0	2.06

Copy the above table of results into your notebook.
Label the blank column 'Power dissipated' in your table of results and calculate the power dissipation for the lamp by using the equation P=IV. (Make sure you put the correct unit in the table column heading!)

Plot a graph of potential difference across the bulb against current flowing through it.

What range of voltages will produce the biggest change in temperature of the bulb?

Why do you think the students carrying out this experiment decided to investigate the voltages between 0V and 1V in more detail?