Question

You view a visible light spectrum from an unknown object. The spectrum appears as a smooth rainbow that fades out on both sides. How was this spectrum produced?

a) By a gas cloud absorbing specific wavelengths
b) By a hot, dense object emitting light at all wavelengths
c) By a solid object reflecting sunlight
d) By a perfectly black object

Answer 1

The smooth rainbow spectrum fading out on both sides is produced by a hot, dense object emitting light at all wavelengths, creating a continuous spectrum.

Step-by-step explanation:

A visible light spectrum produced by an unknown object that appears as a smooth rainbow which fades out on both sides is created by option (b), a hot, dense object emitting light at all wavelengths. This is known as a continuous spectrum, which occurs when a dense substance, like a star, incandescent lightbulb, or heated solid, emits light across the entire range of visible wavelengths. These types of spectra are associated with objects like hot solids, liquids, or condensed gases, and they reflect the unbroken range of colors that such an object can produce when it radiates the excess energy as light. In contrast to this, the spectrum that comes from a gas cloud through which electricity is passed shows only specific wavelengths of light, known as an emission line spectrum, or if that light is seen through a gas cloud, as an absorption line spectrum.