Electromagnetic radiation with a wavelength of 575 nm appears as yellow light to the human eye. the energy of one photon of this light is j.

To find the value of the energy of one photon of electromagnetic radiation, we use the equation,

Here, E is the energy of photon , is the frequency of the light , c is the speed of light and its value of , is the wavelength of the electromagnetic radiation and h is plank constant and its value of .

Given   .

Substituting the values in above equation, we get

Thus, the energy of one photon of electromagnetic radiation is .

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .