Question

Derive an expression for equivalent resistance in series and parallel

Answer 1

Explanation:

Two resistors of resistance R1 and R2 are connected in series. Let I be the current through the circuit. The current through each resistor is also I. The two resistors joined in series is replaced by an equivalent single resistor of resistance R such that the potential difference V across it, and the current I through the circuit remains same.

As , V = IR , V1 = IR1 , V2 = IR2

IR = IR1 + IR2

IR = I (R1 + R2)