Question

Three resistors each having same resistance are connected in parallel. their equivalent resistance is $1\Omega$ if they are connected in series, find the equivalent resistance.

Answer 1

The formula for parallel combination is :

$\frac{1}{R}\left(final\right)=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}$ +……

So if you substitute values , $1\Omega$ $=\frac{1}{R_1}+\frac{1}{R_1}+\frac{1}{R_1}=\frac{3}{R_1}$ .

Solving $R_1$ = 3 $\Omega$.

If we connect all three Resistances,

in series, 3+3+3 = 9 $\Omega$.