Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  JEEMAIN and AIPMT  >>  Physics  >>  Class12  >>  Atoms
0 votes

A photocell is operating in saturation mode with a aphotocurrent 4.8mA when a monochromatic radiation of wavelength $\;3000A^{0}\;$ and power 1mW is incident. When another monochromatic radiation of wavelength $\;1650A^{0}\;$ and power 5mW is incident , it is observed that maximum velocity of photoelectron generation per incident to be same for both cases . Than the threshold wavelength for cell is : The efficiency of photoelectron generation will be

$(a)\;5 \% \qquad(b)\;10 \% \qquad(c)\;15 \% \qquad(d)\;20 \% $

Can you answer this question?

1 Answer

0 votes
Answer : (a) $\;5 \%$
Explanation :
Energy of a photon is first case $\;\large\frac{12400}{3000}=4.13eV$
Rate of incident protons $\;\large\frac{P_{1}}{\varepsilon_{1}}=\large\frac{10^{-3}}{6.6\times10^{-19}}=1.52\times10^{15}\;$ per second
No.of electrons ejected = $\;\large\frac{4.8times10^{-3}}{1.6\times10^{-19}}\;$ per second
$=3\times10^{16}\;$ per second
Efficiency of photoelectron generation = $\;\large\frac{1.52\times10^{15}}{3\times10^{16}}\times100$
$=5 \% \;.$
answered Feb 22, 2014 by yamini.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App