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Introduction to SAT II Physics - FreeExamPapers

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Light is a transverse wave, meaning that it oscillates in a direction perpendicular <strong>to</strong> the<br />

direction in which it is traveling. However, a wave is free <strong>to</strong> oscillate right and left or up<br />

and down or at any angle between the vertical and horizontal.<br />

Some kinds of crystals have a special property of polarizing light, meaning that they<br />

force light <strong>to</strong> oscillate only in the direction in which the crystals are aligned. We find this<br />

property in the crystals in Polaroid disks.<br />

The human eye can’t tell the difference between a polarized beam of light and one that<br />

has not been polarized. However, if polarized light passes through a second Polaroid disk,<br />

the light will be dimmed the more that second disk is out of alignment with the first. For<br />

instance, if the first disk is aligned vertically and the second disk is aligned horizontally,<br />

no light will pass through. If the second disk is aligned at a 45º angle <strong>to</strong> the vertical, half<br />

the light will pass through. If the second disk is also aligned vertically, all the light will<br />

pass through.<br />

Wave Optics on <strong>SAT</strong> <strong>II</strong> <strong>Physics</strong><br />

<strong>SAT</strong> <strong>II</strong> <strong>Physics</strong> will most likely test your knowledge of wave optics qualitatively. That<br />

makes it doubly important that you understand the physics going on here. It won’t do you<br />

a lot of good if you memorize equations involving d sin but don’t understand when and<br />

why interference patterns occur.<br />

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