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STD 12 - 11. Dual nature of radiation and matter — JEE STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceJEESTD 12 - 11. Dual nature of radiation and matter4 Marks
MCQ
A cathode emits $1.8 \times {10^{14}}$ electrons per second, when heated. When $ 400\;V$  is applied to anode all the emitted electrons reach the anode. The charge on electron is $1.6 \times {10^{ - 19}}\;C$. The maximum anode current is ............ $\mu A$
  • A
    $2.7$
  • ✓
    $29$
  • C
    $72$
  • D
    $2.9$
✓

Answer

Correct option: B.
$29$
b
(b) $i = \frac{Q}{t} = \frac{{ne}}{t} = 1.8 \times {10^{14}} \times 1.6 \times {10^{ - 19}} = 28.8 \times {10^{ - 6}}A$

$ = 29\,\mu A$

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