Question

350 nm of light falls on a single slit of width 0.20 mm. What is the angular width of the central diffraction peak?

In a single slit diffraction experiment, if the width of the slit increases, what happens to the width of the central maximum on a screen?

In a double slit experiment, if the separation between the slits increases, what happens to the distance between the interference fringes?

Which of the following colors produces the widest diffraction pattern

		orange
		green
		violet
		red

Answer 1

Given that wave length of light ?=350 x 10-9m
slit width is d=0.2mm=0.2 x 10-3 m
the condition for diffraction maxima is
dsin?=m?
for first order m=1
sin?=?/d
  

so the angula rwidth is

2?= 0.20 deg.....ans

2) It gets narrower.

This is true for single slits, double slits, and diffraction gratings. The smaller the object the wave interacts with, the more spread there is in the interference pattern. Increasing the size of the opening reduces the spread in the pattern.

3)

According to the formula
y = m?L/d
where y = position of bright fringes
m = mth fringe
? = wavelength of light
L = distance between slit and screen
d = separation between slits

If d becomes larger, then y, or the distance between the fringes must DECREASE,

4)

The diffraction grating formula is
n*wavelength = d * sin(x) Sin (x) is what you are interested in.
d is a constant for the grating. and n tells you which fringe you are measuring. So take n = 1 in all cases. All that varies is the wavelength and Sin(x). Sin(x) describes how large the central fringe area is. The larger the wavelength, the larger the fringe area. That would made 680 nm with the largest central area which is red.

RED is the answer