Question

The equivalent resistance between $A$ and $B$ (of the circuit shown) is

• A. $4.5\, \Omega$
• B. $12 \, \Omega$
• C. $5.4 \, \Omega$
• D. $20 \, \Omega$

Answer 1

Answer: (A)

$4.5\, \Omega$

Answer 2

$7\,\Omega ,\,\,3\,\Omega$ are in parallel and $6\,\Omega ,\,\,4\,\Omega$ are in parallel and both combinations are in series. So, $R_{eq}=\frac{7\times 3}{7+3}+\frac{4\times 6}{4+6}$ $\Rightarrow$ $R_{eq}=\frac{21}{10}+\frac{24}{10}$ $\Rightarrow$ $R_{eq}=2.1+2.4$ $\Rightarrow$ $R_{eq}=4.5\,\Omega$