Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The light of wavelength $\lambda^{\prime}$ incident on the surface of metal having work function $\phi$ emits the electrons. The maximum velocity of electrons emitted is $(c=$ velocity of light, h=Planck's constant, m=mass of electron $)$
PhysicsDual Nature of MatterMHT CETMHT CET 2020 (16 Oct Shift 2)
Options:
  • A $\left[\frac{2(\mathrm{~h} \mathrm{C}-\phi)}{\mathrm{m} \lambda}\right]$
  • B $\left[\frac{2(\mathrm{~h} \mathrm{c}-\lambda \phi)}{\mathfrak{m \lambda}}\right]^{\frac{1}{2}}$
  • C $\left[\frac{2(h \mathrm{C}-\lambda)}{m \lambda}\right]^{\frac{1}{2}}$
  • D $\left[\frac{2(\mathrm{~h} \mathrm{v}-\phi) \lambda}{\mathrm{mC}}\right]$
Solution:
2533 Upvotes Verified Answer
The correct answer is: $\left[\frac{2(\mathrm{~h} \mathrm{c}-\lambda \phi)}{\mathfrak{m \lambda}}\right]^{\frac{1}{2}}$
(C)
$\mathrm{hv}-\phi=\mathrm{E}_{\max }=\frac{1}{2} \mathrm{mv}^{2}$
$\frac{\mathrm{hc}}{\lambda}-\phi=\frac{1}{2} \mathrm{mv}^{2}$
$\mathrm{v}^{2}=2 \frac{(\mathrm{hc}-\lambda \phi)}{\lambda \mathrm{m}}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.