Question

The photo electrons emitted from the surface of sodium metal are of

• A. Speeds from 0 to a certain maximum
• B. Same de Broglie wavelength
• C. Same kinetic energy
• D. Same frequency

Answer 1

The correct option is A Speeds from 0 to a certain maximum

$hv=h{v}_0+K.E$
all electrons won't be of same energy as all are not emitted from same degenerate orbit.
$\therefore$ for $hv\ge h{v}_0;K.E\ge 0$
$\Rightarrow$ speed lies between 0 to a maximum value $hv-h{v}_0$.