The threshold wavelength of lithium is 8000 A°. When light of wavelength 9000 A° is made to be incident oh it; then the photo electrons

Question

The threshold wavelength of lithium is 8000 A°. When light of wavelength 9000 A° is made to be incident oh it; then the photo electrons (A) Will not be emitted (B) Will be emitted (C) Will sometimes be emitted and sometimes not (D) Data insufficient

Tardigrade Admin · Accepted Answer

The wavelength of light is inversely proportional to its frequency, hence. threshold frequency of lithium light is

v_{0} \propto \frac{1}{8000}

and the frequency of incident light is

v \propto 19000

From above equations

\frac{1}{8000} > \frac{1}{9000}

\Rightarrow v_{0} > v

Since, threshold frequency is the minimum frequency due to which electron is able to knock out of the surface of metal.
The incident frequency should be more than threshold frequency, therefore no photoelectrons will be emitted.

Q. The threshold wavelength of lithium is 8000 A∘. When light of wavelength 9000 A∘ is made to be incident oh it; then the photo electrons

Will not be emitted

Will be emitted

Will sometimes be emitted and sometimes not

Data insufficient

Q. The threshold wavelength of lithium is 8000 $A^{\circ}$ . When light of wavelength 9000 $A^{\circ}$ is made to be incident oh it; then the photo electrons