Where did the cosmic microwave background (CMB) come from?
a. Photons emitted from the first stars
b. Photons released from hydrogen in our galaxy
c. Light scattered by dust in our Solar System
d. Photons released when electrons and nuclei combined for the first time.
D
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In 1921, Stern and Gerlach performed an experiment that first demonstrated
a. orbital angular momentum quantization b. energy quantization c. space quantization d. magnetic orbital quantization e. that particles behave like waves
Two charged objects attract each other with a certain force. If the charges on both objects are doubled with no change in separation, the force between them
A) becomes zero. B) doubles. C) halves. D) quadruples. E) increases, but we can't say how much without knowing the distance between them.
Tripling the aperture diameter of a camera lens will change the light intensity admitted to the film by what factor?
a. 0.11 b. 0.33 c. 3.0 d. 9.0 e. 12.0
The ______________in a composite material is continuous.
Fill in the blank(s) with the appropriate word(s).