At most, how many bright fringes can be formed on one side of the central bright fringe (not counting the central bright fringe)when light of 625 nm falls on a pair of slits that are $6.77 \times 10 ^ { - 6 } \mathrm {~m}$ apart?
A)10
B)9
C)8
D)11
E)12

Question

Quizplus · Accepted Answer

The number of bright fringes on one side of the central bright fringe is given by:$$N = \frac{aW}{\lambda}-1$$where:* N is the number of bright fringes* a is the distance between the slits* W is the width of the screen* \lambda is the wavelength of lightIn this problem, we have:* a = $6.77 \times 10 ^ { - 6 } \mathrm {~m}$* W = 1 m (since the screen is assumed to be 1 m wide)* \lambda = 625 nm = $6.25 \times 10 ^ { - 7 } \mathrm {~m}$Plugging these values into the equation, we get:$$N = \frac{(6.77 \times 10 ^ { - 6 } \mathrm {~m})(1 \mathrm {~m})}{6.25 \times 10 ^ { - 7 } \mathrm {~m}}-1 = 10$$Therefore, the correct answer is A) 10.

At Most, How Many Bright Fringes Can Be Formed on One