Electric Charges and Fields - Result Question 21
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21. The mean free path of electrons in a metal is $4 \times 10^{-8} m$. The electric field which can give on an average $2 eV$ energy to an electron in the metal will be in units of $V / m$
======= ####21. The mean free path of electrons in a metal is $4 \times 10^{-8} m$. The electric field which can give on an average $2 eV$ energy to an electron in the metal will be in units of $V / m$
3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/electric-charges-and-fields/electric-charges-and-fields—result-question-21.md (a) $5 \times 10^{-11}$
(b) $8 \times 10^{-11}$
(c) $5 \times 10^{7}$
(d) $8 \times 10^{7}$
[2009]
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Answer:
Correct Answer: 21. (c)
Solution:
- (c) Energy $=2 eV$
$\Rightarrow eV_o=2 eV \Rightarrow V_o=2$ volt
$ \begin{aligned} E & =\frac{V_O}{d}=\frac{2}{4 \times 10^{-8}} \\ & =0.5 \times 10^{8}=5 \times 10^{7} Vm^{-1} \end{aligned} $
