what is the history of voltage divider(potential divider)? what is it uses in a circuit? what does it do in a circuit? how does it...

Resisistors are connected in series across  source voltage in order to obtain an output voltage  which is equal to a desired multiple of the source voltage is called the voltage divider or potential divider.

If Vs is the source voltage abd Vo is the out put voltage obtained through the resistor R1 of the resistors R1 and R2 connected in series, then

Vo = (R1*Vs)/(R1+R2) = (R1/R1+R2)*Vs = K* Vs  Thus you can obtain K the factor of output voltage properly chosing the resistors R1 and and R2.

For example if we want to bring down Vo by 1/10 of Vs, we can choose R1 = 1 Ohm, R2=9 Ohm. Then V0 = (1/(1+9)Vs = (1/10)Vs.