Explain why light is referred to as electromagnetic radiation.

Light is a form of electromagnetic radiation because it has the ability to travel from one type of medium to another and can also carry some energy along with it. A light wave has two components, namely the electric field component as well as the magnetic field component that are both perpendicular to the propagating direction.

The visible light lies between the ultraviolet and the infrared lights, with wavelength from 400 nm to 700 nm respectively. This is collectively known as the visible spectrum of light.

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 .