What exactly is resistance in terms of physics?
We all know that resistance was discovered by Ohm and the value is determined by Ohms Law which gives Resistance as the ratio of PD(V) to current(I) ; R=V/I. The cause of resistance is the way the electrons move in a particular material. Metals have a lot of free electrons – there is basically a sea of electrons so electrons move easily through it – so there is little resistance to the flow and they are known as good conductors. Other materials have their electons tightly held around the nuceus of their atoms and so the electrons cannot move easily – so those materials have a high resistance and are known as insulators..
