1.  The violet end of the visible spectrum starts at a wavelength of   ?    µm.

2. The visible spectrum ends with red at a wavelength of    ?     µm.

3. The simulation show that 1 µm = 1000 nm.   

What name is given to nm?

4. What would you say is the colour of the EM “blackbody” source shown at the top as a star burst?

5. Are all three spectral colours - blue, green, red – needed to produce this colour?

6. What is the temperature shown for this EM blackbody source at the beginning, when you open the simulation?

7. What would this temperature be in Celsius?

8. What is the frequency of red light?

9. At what temperature would an oven heating element just begin to glow red?

10. What does this simulation assume is the average temperature of the earth’s surface?

 What would this be in Celsius?

11. We see the earth by reflected light, but why don’t we see the earth glowing except at a few spots where there is an active volcano?

Which of our senses would let us detect the EM radiation being given off by the earth?

12. According to this simulation, what is the colour of an operating incandescent light bulb?

13. Which spectral primary colour is needed the least to produce the light bulb colour?

14. Is an incandescent light bulb primarily a light source or a heat source?

14. How does this simulation help answer the previous question?