7. An X-ray tube operating at 30 kV emits continuous X-rays with k min ¼
0:414 ˚
A; the Planck’s constant can found to be:
(a) 6.324 Â 10
–34 J-s
(b) 6.424 Â 10
–34 J-s
(c) 6.524 Â 10
–34 J-s
(d) 6.624 Â 10
–34 J-s
8. An X-ray tube is operating at 40 kV and tube current 25 mA. The power input
in the tube is:
(a) 800 W
(b) 900 W
(c) 1000 W
(d) 1100 W
9. An X-ray tube is operating at 40 kV and tube current 25 mA. If the power is
maximum achievable in this tube, then the maximum permissible tube current
at 50 kV is:
(a) 20 mA
(b) 30 mA
(c) 40 mA
(d) 50 mA
10. For platinum metal, the energy levels K, L and M lie roughly at 78, 12 and
3 eV, respectively. The approximate wavelength of characteristic K a line is:
(a) 0.09 Å
(b) 0.19 Å
(c) 0.29 Å
(d) 0.39 Å
11. For platinum metal, the energy levels K, L and M lie roughly at 78, 12 and
3 eV, respectively. The approximate wavelength of characteristic K b line is:
(a) 0.37 Å
(b) 0.27 Å
(c) 0.17 Å
(d) 0.07 Å
12. The wavelength of L a (X-ray line) of platinum (atomic number 78) is 1.321 Å.
An unknown element emits L a X-rays of wavelength 4.174 Å. If the value of b
for L a is 7.4, the atomic number of unknown element is:
(a) 17.1
(b) 27.1
(c) 37.1
(d) 47.1
7.4 Other Diffraction Methods
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