tell me all the formula of of this chapter electricity along with their derivation

Electric Power Formulas

P = V I 

P = R I² 

P = V²/ R

where

P = power (Watts)

V = voltage (Volts)

I = current (Amperes)

R = resistance (Ohms)

Electric Current Formulas

I = V / R

I = P / V

Electric Resistance Formulas

R = V / I

R = V²/ P

R = P / I²

Electrical Potential Formulas - Ohms Law

Ohms law can be expressed as:

V = R I

V/I=R