Mounted lamp

[Xenon]

Physics teacher has asked me to get a '12V mounted lamp' that changes colour as the voltage is racked up from 2V to the 12 Volts. Anyone got one/know a supplier?

[rosaliemb]

I have used the llight in the Hodson Light Box set, kept in it's ray box which acts as a bit of a light shield. Not spectacular colour change. We used it to demonstrate light colour relationship with temperature for stars.
Rosalie(another one)

[dime]

The regular lamps on stands that are used for electricity pracs operate like that. They glow brighter with more volts, say 2 to 12. Is that too simple, or am I missing something?

[Xenon]

The colour would have to depend on the filament material rather than the voltage, but when I got back to Teach she was talking about detecting colour changes from red to orange to yellow as the 12 Volt bulb heats up from 2V to 12V, but hard to do with out a very sensitive bulb.
Should I tell her she's dreaming?