35. A beam of X-ray having wavelengths in the range 0:2 ˚
A to 1 ˚
A is allowed to
incident at an angle of 9° with the cube face of rock-salt crystal d ¼ 2:814 ˚
A
À
Á :
For the diffracted beam, the minimum allowed value of the wavelength is:
(a) 0.12 Å
(b) 0.22 Å
(c) 0.32 Å
(d) 0.42 Å
36. The angles for the first-order reflection from (100), (110) and (111) face of
sodium chloride crystals using monochromatic X-rays are 5.9°, 8.4° and 5.2°,
respectively. Nature of the given crystal is:
(a) S C
(b) B C C
(c) F C C
(d) D C
37. A crystal plane is mounted on an X-ray spectrometer. The glancing angles of
incidence for three reflections are 5° 58′, 12° 01′ and 18° 12′, respectively. If
the wavelength of the X-rays used is 0.586 Å, the average value of the interplanar spacing will be:
(a) 5.817 Å
(b) 4.817 Å
(c) 3.817 Å
(d) 2.817 Å
38. The linear attenuation coefficient for aluminum is 139 m
À1 for K a line emitted
by a tungsten target in an X-ray tube. The percentage of intensity of this X-ray
will pass through 0.005 m thick aluminum sheet is:
(a) 40%
(b) 50%
(c) 60%
(d) 70%
39. The attenuation percentage in an X-ray beam after passing through a thickness
of a material equal to four-half value thickness:
(a) 93.7%
(b) 83.7%
(c) 73.7%
(d) 63.7%
294
7 Diffraction of Waves and Particles by Crystal
A to 1 ˚
A is allowed to
incident at an angle of 9° with the cube face of rock-salt crystal d ¼ 2:814 ˚
A
À
Á :
For the diffracted beam, the minimum allowed value of the wavelength is:
(a) 0.12 Å
(b) 0.22 Å
(c) 0.32 Å
(d) 0.42 Å
36. The angles for the first-order reflection from (100), (110) and (111) face of
sodium chloride crystals using monochromatic X-rays are 5.9°, 8.4° and 5.2°,
respectively. Nature of the given crystal is:
(a) S C
(b) B C C
(c) F C C
(d) D C
37. A crystal plane is mounted on an X-ray spectrometer. The glancing angles of
incidence for three reflections are 5° 58′, 12° 01′ and 18° 12′, respectively. If
the wavelength of the X-rays used is 0.586 Å, the average value of the interplanar spacing will be:
(a) 5.817 Å
(b) 4.817 Å
(c) 3.817 Å
(d) 2.817 Å
38. The linear attenuation coefficient for aluminum is 139 m
À1 for K a line emitted
by a tungsten target in an X-ray tube. The percentage of intensity of this X-ray
will pass through 0.005 m thick aluminum sheet is:
(a) 40%
(b) 50%
(c) 60%
(d) 70%
39. The attenuation percentage in an X-ray beam after passing through a thickness
of a material equal to four-half value thickness:
(a) 93.7%
(b) 83.7%
(c) 73.7%
(d) 63.7%
294
7 Diffraction of Waves and Particles by Crystal