Talk about all the laws used in ohm's law, for example, the total voltage of a series circuit is equal to the sum of the voltages of its parts.

1.i = u/r (ohm's law: the current in a conductor is directly proportional to the voltage across the conductor and inversely proportional to the resistance of the conductor).

2.I = i 1 = I2 = … = In (characteristics of current in series circuit: current is equal everywhere).

3.U = U 1+U2+…+UN (characteristics of voltage in series circuit: in series circuit, the total voltage is equal to the sum of voltages at both ends of each part of the circuit).

4.I = i 1+I2+…+In (characteristics of current in parallel circuit: the current on the main line is equal to the sum of currents in each branch).

5.U = U 1 = U2 = … = UN (characteristics of voltage in parallel circuit: the voltages at both ends of each branch are equal. Equal to the supply voltage)

6.R = r 1+R2+…+RN (characteristics of resistors in series circuit: total resistance is equal to the sum of the resistances of all parts)

7.1/r =1/r1+1R2+…+1/rn (characteristics of resistors in parallel circuits: the reciprocal of the total resistance is equal to the sum of the reciprocal of all parallel resistances).

8.R and = R/n(n (formula for calculating total resistance when n identical resistors are connected in parallel)

9.R series = NR (formula for calculating total resistance when n identical resistors are connected in series)

10.u1:U2 = r1:R2 (the relationship between voltage and resistance in series circuit: the ratio of voltage is equal to the ratio of their corresponding resistances).

11.i1:i2 = r2: r1(the relationship between current and resistance in parallel circuit: the ratio of current is equal to the inverse ratio of their corresponding resistances).