Question
Light of frequency $1.5$ times the threshold frequency Is incident on a photosensitive material. What will be the photoelectric current if the frequency is halved and intensity is doubled$?$
✓
Answer
$K _{1}=1.5 hv _{0}-\phi_{0}=0.5 hvo$
$K _{2}=\frac{1.5}{2} h { v }_ 0- h v_ 0=-0.25 h v_{ 0}$
$\because$ Kinetic energy can never be negative So, no emission and $i=0$
OR
In second case the incident frequency is halved
Incident frequency $=\frac{1.5}{2} v_{0}=0.75 v _{0}$
Now the incident frequency is less than threshold frequency so no emission of electron take place therefore no current. $(i=0)$
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