Blackbody Radiation Curve.

Change the temperature:  


All objects above absolute zero Kelvin emit a broad range of electromagnetic radiation called blackbody radiation. Normally we cannot see this radiation unless a significant portion of the wavelengths lie in the visible part of the spectrum.

The graph shows a plot of the blackbody curve for the temperature you choose. Colors in the graph indicate the visible portion of the spectrum: 400 (blue), 500 (green), and 600 (red) nanometers. The colored circles on the left represent the percent of each color present and a simulation of the total color of the object.

Question 1:

The peak of the blackbody spectrum is related to the temperature of the object by Wien's law. Only when objects are very hot does the peak of the spectrum lie in the visible wavelength range. For which of the following temperatures is the peak of the black body curve in the middle of the visible spectrum?

Question 2:

For which of the following temperatures will and object appear red?

Question 3:

A light bulb filament is white hot (appears white) while it is lit. Based on the above questions, about what temperature is it?

Question 4:

An electric stove element is red hot. Based on the above questions, about what temperature is it?

Question 5:

What is the apparent color of an object at room temperature (300 Kelvin) if there is no other light source?

Question 6:

We see objects in a room at room temperature, not because of their blackbody radiation but because of reflected light from a source at a higher temperature (a light bulb filament for example). What would a room look like if everything were at the same temperature as the light bulb filament? (This is in fact why it is difficult to view objects inside a kiln used to fire ceramics: due to the high temperature there is plenty of light but everything has the same color.)