Question

(a) Three resistors $1\Omega ,2\Omega$ and $3\Omega$ are combined in series. What is the total resistance of the combination?

(b) If the combination is connected to a battery of emf 12 V and negligible internal resistance, obtain the potential drop across each resistor.

Answer 1

(a)

Equivalent resistance is
$R_{eq}=R_1+R_2+R_3=(1+2+3)\Omega =6\Omega$

(b)

Current in the circuit is given by $I=\frac{E}{R}$

$I=\frac{12}{6}=2\Omega$

Potential drop across $1\Omega ,V_1=I{R}_1=2\times 1=2V$

Potential drop across $2\Omega ,V_2=I{R}_2=2\times 2=4V$

Potential drop across $3\Omega ,V_3=I{R}_3=2\times 3=6V$