Find RTh in the following network:

Concept

When 'n' resistors are connected in series, the equivalent resistance is given by:

\(R_{eq}=R_1+R_2.........R_n\)

When 'n' resistors are connected in parallel, the equivalent resistance is given by:

\({1\over R_{eq}}={1\over R_1}+{1\over R_2}.........{1\over R_n}\)

Calculation

For the given circuit, 6 Ω and 12 Ω are connected in parallel.

\(R={6\times 12\over 6+12}=4Ω\)

Now 4Ω, 3Ω and 2Ω are connected in series.

\(R_{th}=4\Omega+3\Omega+2\Omega\)

\(R_{th}=9\Omega\)