Unit: Waves
Year: 1990 Question#: 59
Question: Monochromatic light passes through two parallel narrow slits and forms an interference pattern on a screen. As the distance between the two slits is increased, the distance between light bands in the pattern on the screen will
(1 ) decrease
(2 ) increase
(3 ) remains the same
What is this question really asking?
Explanation by: Gabriel F
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Answer 1
A) decrease
CORRECT
If you look at the formula
when the distance (d) increases then the separation between peaks (x) has to decrease.
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Answer 2
increase
INCORRECT
Make sure you are using the formula
correctly.
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Answer 3
remains the same
INCORRECT
Answer C is incorrect because when the distance is changed, something else in the ratio has to change and it just turns out to be the light bands (peaks).
Make sure you are using the formula
correctly.
return to top What's this question really asking? What is the relationship between the two slits for waves and the distance between light bands in the pattern on the screen. return to top
