21.4 Series and Parallel Combinations of Resistances

The Series Combination

From Kirchoff's First Law, also known as KCL ( Kirchoff's Current law), it is obvious that the current i flowing through each resistance is the same.

From Kirchoff's Second Law, also known as KVL (Kirchoff's Voltage Law).

Parallel Combination

At junction Q (- i ) + (+ i₁) + (+ i₂) + ( i₃) = 0 by KCL.

\    i = i₁ + i₂ + i₃

Around the loop PQLORSP

V_PQ + V_QL + V_OR + V_LO + V_RS + V_SP = 0

0 + 0 + (-i₁ R₁ ) + 0 + 0 + E = 0

(The potential difference across connecting wires is taken as zero)

Index

21.1 Electric Current
21.2 Ohm'z Law
21.3 Kirchoff's Laws
21.4 Series and Parallel combination of Resistance

Chapter 23