Question

Four resistance $5\Omega$, $10\Omega$, $15\Omega$ and an unknown $X\Omega$ are connected in series so as to form Wheatsones network. Determine the unknown resistance $X$, if the network is balance with these numerical values of resistances.

Answer 1

Given :

$R_1=5\Omega$

$R_2=10\Omega$

$R_4=15\Omega$

$R_3=x$

To find :

unknown resistance $R_3=x$ = ?

since the network is balanced.

$\frac{R_1}{R_2}-\frac{R_3}{R_4}$

$\frac{5}{10}-\frac{x}{15}$

$x=\frac{5\times 15}{10}-\frac{75}{10}$

$x=7.5\Omega$