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 beam of x rays of wavelength 0.10 nm is found to diffract in second order from the face of a LiF crystal at a Bragg angle of 30 $\degree$ . The distance between adjacent crystal planes is about:

In a double-slit diffraction experiment the number of interference fringes within the central diffraction maximum can be increased by:

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:

As more slits with the same spacing are added to a multiple-slit system the lines:

Light of wavelength 550 nm is incident on a diffraction grating that is 1 cm wide and has 1000 slits. What is the dispersion of the m = 2 line?

At a bright diffraction line phasors associated with waves from the slits of a multiple-slit barrier:

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

Radio waves are readily diffracted around buildings whereas light waves are negligibly diffracted around buildings. This is because radio waves:

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:

A person with her eye relaxed looks through a diffraction grating at a distant monochromatic point source of light. The slits of the grating are vertical. She sees:

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:

The diagram shows a single slit with the direction to a point P on a distant screen (not shown). At P, the pattern has its second minimum (from its central maximum). If X and Y are the edges of the slit, what is the path length difference (PX) - (PY)?

A beam of white light (from 400 nm for violet to 700 nm for red) is normally incident on a diffraction grating. It produces two orders on a distant screen. Which diagram below (R = red, V = violet) correctly shows the pattern on the screen?

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:

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

The resolving power of a telescope can be increased by:

A diffraction grating of width W produces a deviation $\theta$ in second order for light of wavelength $\lambda$ . The total number N of slits in the grating is given by:

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°?

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: