Electronic Devices and Circuits - Engineering

Q1:

As per Einstein's equation, the velocity of emitted electron in photoelectric emission is given by the equation

A
mv2 = hf - Uw

B
mv2hf - Uw

C
mv2 = hf + Uw

D
mv2hf + Uw

ANS:B -

mv2hf - Uw

Some electrons have less energy than Fermi level E and, therefore, more energy than Uw to escape. Therefore, this equation has inequality sign.