Question

the threshold photoelectric effects in Tungsten is produced by light of a wavelength 260 nm give the energy of a photon of this light in Joules. ​

Answer 1

Energy of light is
`7.62* 10^(-17) \ Joules`

Step-by-step explanation:

Given:

Wavelength
`(\lambda)=260 \ nm=2.60 * 10^(-7) m`

Also we know the speed of light
`(c) =3 * 10^8 \ m/s`

To calculate frequency of light
`(v)`, divide speed of light
`(c)` by Wavelength
`(\lambda)`

`v= (3 * 10^8)/(2.60* 10^(-7))= 1.15* 10^(15) \ per \ second`

Hence frequency is
`1.15* 10^(15) \ per \ second`

Now, To calculate energy (E), we need to multiply planks's constant
`(h)` with the frequency of light
`(v)`.

Also Plank's Constant
`(h)` =
`6.626* 10^(-34)\ J \ s`

`E = h *. f = 6.626* 10^(-34)\ J \ s * 1.15 * 10^(15)\ s^(-1) = 7.62 * 10^(-19) \ J`

Hence Energy of light is
`7.62* 10^(-19) \ Joules`