Dual Nature of Radiation and Matter - Result Question 45
47. A 5 watt source emits monochromatic light of wavelength $5000 \AA$. When placed $0.5 m$ away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of $1.0 m$, the number of photoelectrons liberated will be reduced by a factor of [2007]
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======= ####47. A 5 watt source emits monochromatic light of wavelength $5000 \AA$. When placed $0.5 m$ away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of $1.0 m$, the number of photoelectrons liberated will be reduced by a factor of [2007]
c3eec34ec6b1fad69db54a20ad4b2dca40c2aa54 (a) 8
(b) 16
(c) 2
(d) 4
Show Answer
Answer:
Correct Answer: 47. (d)
Solution:
- (d) Number of emitted electrons $N_E \propto$ Intensity
$\propto \frac{1}{(\text{ Distance })^{2}}$
Therefore, as distance is doubled, $N_E$ decreases by $(1 / 4)$ times.
