Question

Please answer the question​

Answer 1

Energy of light wave falling,

$E = \frac{1240 * 10^{-9}}{\lambda}$

where λ is in nanometre

$E = \frac{1240*10^{-9}}{400 * 10^{-9}} eV \\\\E = 3.1 eV$

Since, work function is lower than incident energy, emission will take place.

Maximum kinetic energy = incident energy - work function

= 3.1 - 1.1

= 2eV