Question

For the diffraction from a single slit, the intensity of the central point is:
A) Infinite
B) Finite and the same magnitude as the surrounding maxima
C) Finite but much larger than the surrounding maxima
D) Finite and substantially smaller than the surrounding maxima
E) Zero

Answer 1

Hint: We know that width of the central maxima is greater than the surrounding maxima. Also we know that intensity is directly proportional to the width of the slit. By this we just have to conclude the pattern formed by the process and then we can match the given option.

Complete answer:
We know that single slit diffraction involves sending a beam of light or electrons or other objects through a single slit.
While double-slit diffraction involves two slits. With a single very narrow (comparable to the wavelength of the beam) slit, the beam diffracts broadly in all directions behind the slit and spreads all over a downstream viewing screen.
With two narrow slits, the beams from both slits also diffract broadly but now the two beams overlap, creating an interference pattern at the viewing screen.
So a single narrow slit creates broad diffraction with no interference, while a double slit creates broad diffraction with regions of constructive interference and regions of destructive interference.
A single slit pattern is much different than the double slit one. This is because of the missing concept of coherency.This leads to the monotonic nature of the waves formed due to the single slit pretty different from the double slit experiment conducted.
Now, in a single slit diffraction pattern, the intensity of the central point of the fringe is finite. It leads to the dismissal of the first option.Single slit diffraction pattern is mostly much larger when compared to the secondary maxim surrounding it.
In one sentence we can say that the intensity of the central maxima is directly proportional to width of the slit and since the width of the central maxima is larger than surrounding hence the intensity is is larger than the surrounding as well as finite.
Hence intensity is finite but much larger than the surrounding maxima.

Therefore, the right option is option C.

Note: In a single slit diffraction, light spreads out in a line perpendicular to the slit. But in a double slit diffraction, light refracts when passing through the slits, but the light waves coming out from those slits interfere with each other to produce an interference pattern on the screen.