Relative electrical energy consumption for different light bulb color temperatures

[songoku]

Homework Statement

Please see below

Relevant Equations

maybe:

λmax . T = constant and E = hf

I am not sure what the context of the question is. I am thinking this question is about light bulb emitting different colour at different temperature. The higher the temperature, the lower the wavelength hence the higher the energy emitted by the bulb so the energy consumption will also be higher.

My answer is (C) but correct answer is (B). What is my mistake?

Thanks

 

[mjc123]

The question says the intensity is the same for each colour. Do you know the definition of "intensity"?

 

[songoku]

The question says the intensity is the same for each colour. Do you know the definition of "intensity"?

Intensity is power / area, so it means the power is the same and the energy consumption will be the same.

Thank you very much mjc123

 

[nasu]

The energy consumption is given by the power rating of the bulb. If it's an incandescent bulb, the power of the light emitted is just a small percentage of the electrical power. And there is no simple correlation between the two powers as a function of filament temperature. They may be emitting same power of light but this does not mean they use the same electrical power.