A photon of energy h v is absorbed by a free electron of a metal having work function φ

Question

A photon of energy h v is absorbed by a free electron of a metal having work function φ< h v (A) The electron is sure to come out. (B) The electron is sure to come out with a kinetic energy h v-φ (C) Either the electron does not come out or it comes out with a kinetic energy h v-φ (D) It may come out with a kinetic energy less than h v-φ

Tardigrade Admin · Accepted Answer

K max =h v-φ . As 0 < K < K max ⇒ K < (h v-φ)

Q. A photon of energy $h v$ is absorbed by a free electron of a metal having work function $ϕ < h v$

The electron is sure to come out.

The electron is sure to come out with a kinetic energy $h v - ϕ$

Either the electron does not come out or it comes out with a kinetic energy $h v - ϕ$

It may come out with a kinetic energy less than $h v - ϕ$

$K_{m a x} = h v - ϕ .$ As $0 < K < K_{m a x} \Rightarrow K < (h v - ϕ)$

Q. A photon of energy hv is absorbed by a free electron of a metal having work function ϕ<hv

The electron is sure to come out.

The electron is sure to come out with a kinetic energy hv−ϕ

Either the electron does not come out or it comes out with a kinetic energy hv−ϕ

It may come out with a kinetic energy less than hv−ϕ

Kmax​=hv−ϕ. As 0<K<Kmax​⇒K<(hv−ϕ)

Q. A photon of energy $h v$ is absorbed by a free electron of a metal having work function $ϕ < h v$

The electron is sure to come out with a kinetic energy $h v - ϕ$

Either the electron does not come out or it comes out with a kinetic energy $h v - ϕ$

It may come out with a kinetic energy less than $h v - ϕ$

$K_{m a x} = h v - ϕ .$ As $0 < K < K_{m a x} \Rightarrow K < (h v - ϕ)$