Exam 36: Diffraction

When 450-nm light is incident normally on a certain double-slit system the number of interference maxima within the central diffraction maximum is 5.When 900-nm light is incident on the same slit system the number is:

A diffraction grating just resolves the wavelengths 400.0 nm and 400.1 nm in first order.The number of slits in the grating is:

Which of the following is true for Bragg diffraction but not for diffraction from a grating?

A diffraction pattern is produced on a viewing screen by illuminating a long narrow slit with light of wavelength $\lambda$ .If $\lambda$ is increased and no other changes are made:

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

The rainbow seen after a rain shower is caused by:

The dispersion D of a grating can have units:

The widths of the lines produced by monochromatic light falling on a diffraction grating can be reduced by:

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:

Light of wavelength 480 nm falls on a slit of width 3.5 µm.What is the relative intensity (that is, the value of I/I_m)of the diffraction pattern at an angle of 18°?

Figure (i)shows a double-slit pattern obtained using monochromatic light.Consider the following five possible changes in conditions: Which of the above would change Figure (i)into Figure (ii)?

If white light is incident on a diffraction grating:

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:

At the second minimum adjacent to the central maximum of a single-slit diffraction pattern the Huygens wavelet from the top of the slit is 180 $\degree$ out of phase with the wavelet from:

Two nearly equal wavelengths of light are incident on an N slit grating.The two wavelengths are not resolvable.When N is increased they become resolvable.This is because:

What is the minimum number of slits required in a diffraction grating to just resolve light with wavelengths of 471.0 nm and 471.6 nm?

When the atmosphere is not quite clear, one may sometimes see colored circles concentric with the Sun or the Moon.These are generally not more than a few diameters of the Sun or Moon and invariably the innermost ring is blue.The explanation for these phenomena involves:

In the equation sin $\theta$ = $\lambda$ /a for single-slit diffraction, $\theta$ is:

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

Two wavelengths, 800 nm and 600 nm, are used separately in single-slit diffraction experiments.The diagram shows the intensities on a far-away viewing screen as function of the angle made by the rays with the straight-ahead direction.If both wavelengths are then used simultaneously, which point corresponds to the smallest angle at which the light on the screen is purely 800-nm light?