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If two light bulbs are placed side by side in front of a screen, no interference

ID: 1290547 • Letter: I

Question

If two light bulbs are placed side by side in front of a screen, no interference is observed. Why?

Each bulb produces only one wavelength of light

Each bulb produces many wavelengths of light

Incandescent light is incoherent

Incandescent light is so coherent that its wavelengths never get out of phase with one another

When you hold up a CD to the light, you see a colorful rainbow on its surface. This occurs because the CD acts as a _____ which produces color by _______

Prism; Diffraction

Transmission Grating; Interference

Reflection Grating; Interference

Prism; Dispersion

Light impinges on a slit but suffers very little diffraction. We conclude that the wavelength of the light is A. Much shorter than the slit width B. Much longer than the slit width C. About the same order as the slit width D. We cannot say anything about the wavelength

A.

Each bulb produces only one wavelength of light

B.

Each bulb produces many wavelengths of light

C.

Incandescent light is incoherent

D.

Incandescent light is so coherent that its wavelengths never get out of phase with one another

Explanation / Answer

1)

Incandescent light is incoherent

2)

Transmission Grating; Interference

C.

Incandescent light is incoherent

2)

B.

Transmission Grating; Interference