Chapter 33: Q. 8 (page 954)

a. Green light will shine through a hole with a $100 - m m$ -diameter hole of and is seen on a screen. Does the circular point of lights $20 %,$ is on the screen shrink in diameter, rise in diameter, or remain the same in diameter by? Explain.
b. Green light will shine through a hole with a $100 - μ m$ diameter of and is seen on a screen. Does the circular point of lights is $20 %,$ on the screen shrink in diameter, rise in diameter, or remain the same in diameter by? Explain.

Short Answer

Expert verified

a. The diameter of the light spot on the screen increases.

b. The diameter of the light spot on the screen decreases.

Step by step solution

Circular spot of light on the Screen

(a) Enlarging the hole will extend the size of the screen spot. The reason for this is that when the diameter grows larger, ray optical will take precedence over wave optics.

(b) Expanding the hole larger will reduce the size of the screen spot. When the hole is less than 1, or of same order as the wavelength, we must consider diffraction effects.

The diameter of the light spot on the screen decreases.

In this case, the wavelet transforms do not interact. Because the size of the center max is proportional to the area of the hole, the diameter of the light spot on the screen shrinks as the hole diameter grows. The hole's diameter is inversely related to the size of a central maximum. Because the hole is too big to see, the diffraction increase aren't visible.