Question

Twelve identical resistors of 6 $\Omega$ each are connected to form a cube as shown above. The effective resistance across the solid diagonal, AG is :

• A. $5\Omega$
• B. $4.5\Omega$
• C. $3.5\Omega$
• D. $1.5\Omega$

Answer 1

The correct option is A $5\Omega$

$I{R}_{eff}=V$
$\frac{I}{3}\times R+\frac{I}{6}\times R+\frac{I}{3}\times R=I{R}_{eff}$
$R[\frac{2}{3}+\frac{1}{6}]=R_{eff}$
$R_{eff}=\frac{R\times 15}{18}$
$R_{eff}=5\Omega$