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12. atoms — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics12. atoms1 Mark
MCQ
An $X-$ ray machine has an accelerating potential difference of $25,000$ volts. By calculation the shortest wavelength will be obtained as.......$\mathop A\limits^o $ ($h = 6.62 \times {10^{ - 34}}$ J-sec; e = $1.6 \times {10^{ - 19}}$coulomb)
  • A
    $0.25$
  • ✓
    $0.50 $
  • C
    $1$
  • D
    $2.50$
✓

Answer

Correct option: B.
$0.50 $
b
(b) ${\lambda _{\min }} = \frac{{hc}}{{eV}} = \frac{{12375}}{V}\,{Å}$ $ = 0.495\,\,{Å} \approx 0.5\,{Å}$

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