Question

The work function of a photoelectric material is 4.0 eV. (a) What is the threshold wavelength ?

Answer 1

$\textbf{Hello Mate}$

$\textbf{Question}$>>>>>The work function of a photoelectric material is 4.0 eV. (a) What is the threshold wavelength ?

$\textbf{Answer}$>>>>

By using the work function formulla>>>>

w' = $\frac{hc}{λ}$....(1)

where w' is work function of material.

h is Planck constant and the value of Planck constant is 6.62 x $\upper{10}^{-34}$.

c is the velocity of light.

λ is the threshold wavelength.

Now Acc. to Question>>>

The work function is given in the form of 4.0ev

So firstly we have to convert this into simple form.
To covert this into simple form we have to multiply given 4.0ev with charge of electron.

The charge of electron= 1.6 x $\upper{10}^{-19}$

So we get>>>>

w' = 4.0 x 1.6 x $\upper{10}^{-19}$

w' = 6.4 x $\upper{10}^{-19}$

Now using first equation we get>>>>

λ = $\frac{hc}{w'}$

So We get>>>>>

λ = 3.10 x $\upper{10}^{-7}$ m.

So threshold frequency is 3.10 x $\upper{10}^{-7}$ m.

Be Brainly.

@karangrover12