Energy Carried by Electromagnetic Waves Video Lessons

Concept

# Problem: Which of the following occurs as light travels farther from its source? (1 point)a. Far from the source, photons come together in a small area.b. The intensity of light increases as photons move away from the source.c. The source gives off less light as photons move away from it.d. Far from the source, photons spread over a larger area.

###### FREE Expert Solution

We are required to state the effect of one of the laws governing brightness.

Apparent brightness:

$\overline{){\mathbf{B}}{\mathbf{=}}\frac{\mathbf{L}}{\mathbf{4}\mathbf{\pi }{\mathbf{d}}^{\mathbf{2}}}}$ where B is apparent brightness, L is intrinsic luminosity, and d is the distance from the source.

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###### Problem Details

Which of the following occurs as light travels farther from its source? (1 point)
a. Far from the source, photons come together in a small area.
b. The intensity of light increases as photons move away from the source.
c. The source gives off less light as photons move away from it.
d. Far from the source, photons spread over a larger area.