Search any question & find its solution
Question:
Answered & Verified by Expert
A stream of photons having energy $3 \mathrm{eV}$ each impinges on a potassium surface. The work function of potassium is $2.3 \mathrm{eV}$. The emerging photo-electrons are slowed down by a copper plate placed $5 \mathrm{~mm}$ away. If the potential difference between the two metal plates is $1 \mathrm{~V}$, the maximum distance the electrons can move away from the potassium surface before being turned back is-
Options:
Solution:
2012 Upvotes
Verified Answer
The correct answer is:
$3.5 \mathrm{~mm}$
$\mathrm{K}=3-2.3=0.7 \mathrm{eV}, \mathrm{S}=\frac{\mathrm{K}}{\mathrm{eE}}$ and $\mathrm{E}=\mathrm{V} / \mathrm{d}$
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.