Exam 36: Diffraction

When a highly coherent beam of light is directed against a very fine wire, the shadow formed behind it is not just that of a single wire but rather looks like the shadow of several parallel wires. The explanation of this involves:

The rainbow seen after a rain shower is caused by:

Light of wavelength $\lambda$ is normally incident on some plane optical device. The intensity pattern shown is observed on a distant screen ( $\theta$ is the angle measured to the normal of the device). The device could be:

A light beam incident on a diffraction grating consists of waves with two different wavelengths. The separation of the two first order lines is great if:

Two slits in an opaque barrier each have a width of 0.020 mm and are separated by 0.050 mm. When coherent monochromatic light passes through the slits the number of interference maxima within the central diffraction maximum:

If 550-nm light is incident normally on a diffratction grating and exactly 6 lines are produced. The ruling eparation must be:

Two slits of width a and separation d are illuminated by a beam of light of wavelength $\lambda$ . The separation of the interference fringes on a screen a distance D away is:

The shimmering or wavy lines that can often be seen near the ground on a hot day are due to:

Bragg's law for x-ray diffraction is 2d sin $\theta$ = m $\lambda$ , the quantity d is:

An N-slit system has slit separation d and slit width a. Plane waves with intensity I and wavelength $\lambda$ are incident normally on it. The angular separation of the lines depends only on:

The dispersion D of a grating can have units:

The resolving power R of a grating can have units:

For a certain multiple-slit barrier the slit separation is 4 times the slit width. For this system:

To obtain greater dispersion by a diffraction grating:

Consider a single-slit diffraction pattern caused by a slit of width a. There is a maximum if sin $\theta$ is equal to:

No fringes are seen in a single-slit diffraction pattern if:

The resolving power of a diffraction grating is defined by R = $\lambda$ / $\Delta$ $\lambda$ Here $\lambda$ and $\lambda$ + $\Delta$ $\lambda$ are:

The spacing between adjacent slits on a diffraction grating is 3 $\lambda$ . The deviation $\theta$ of the first order diffracted beam is given by:

The intensity at a secondary maximum of a single-slit diffraction pattern is less than the intensity at the central maximum chiefly because:

A plane wave with a wavelength of 500 nm is incident normally on a single slit with a width of 5.0 *10^-6 m. Consider waves that reach a point on a far-away screen such that rays from the slit make an angle of 1.0 $\degree$ with the normal. The difference in phase for waves from the top and bottom of the slit is: