Dual Nature of Radiation and Matter - Result Question 49
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51. A photosensitive metallic surface has work function, $h v_0$. If photons of energy $2 h v_0$ fall on this surface, the electrons come out with a maximum velocity of $4 \times 10^{6} m / s$. When the photon energy is increased to $5 h v_0$, then maximum velocity of photoelectrons will be
======= ####51. A photosensitive metallic surface has work function, $h v_0$. If photons of energy $2 h v_0$ fall on this surface, the electrons come out with a maximum velocity of $4 \times 10^{6} m / s$. When the photon energy is increased to $5 h v_0$, then maximum velocity of photoelectrons will be
3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/dual-nature-of-radiation-and-matter/dual-nature-of-radiation-and-matter—result-question-49.md (a) $2 \times 10^{7} m / s$
(c) $8 \times 10^{6} m / s$
(b) $2 \times 10^{6} m / s$ [2005]
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Answer:
Correct Answer: 51. (c)
Solution:
- (c) We know that
$h v-\phi=K _{\max }=\frac{1}{2} m v _{\max }^{2}$
According to question
$\frac{5 h v_0-h v_0}{2 h v_0-h v_0}=\frac{v_2^{2}}{v_1^{2}}$
$v_2=2 v_1=2 \times 4 \times 10^{6}=8 \times 10^{6} m / s$.
