Dual Nature of Radiation and Matter - Result Question 39
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41. The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work function $5.01 eV$, when ultraviolet light of $200 nm$ falls on it, must be:
======= ####41. The potential difference that must be applied to stop the fastest photoelectrons emitted by a nickel surface, having work function $5.01 eV$, when ultraviolet light of $200 nm$ falls on it, must be:
3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/dual-nature-of-radiation-and-matter/dual-nature-of-radiation-and-matter—result-question-39.md (a) $2.4 V$
(b) $-1.2 V$
(c) $-2.4 V$
(d) $1.2 V$
[2010]
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Answer:
Correct Answer: 41. (b)
Solution:
- (b) $K _{\max }=\frac{h c}{\lambda}-W=\frac{h c}{\lambda}-5.01$
$=\frac{12375}{\lambda(\text{ in } \AA)}-5.01$
$=\frac{12375}{2000}-5.01=6.1875-5.01=1.17775$
$\simeq 1.2 V$
The potential difference that must be applied to stop photoelectrons $=-1.2 V$
