Question

What is the maximum resistance which can be made using five resistors each of $\frac{1}{5}\Omega$?

• A. $\frac{1}{5}\Omega$
• B. $10\Omega$
• C. $5\Omega$
• D. $1\Omega$

Answer 1

The correct option is D

$1\Omega$

Step 1:Given:

The number of resistors $n=5$.

Each resistance$R=\frac{1}{5}\Omega$.

Step 2:Maximum resistance is obtained when resistors are connected in series: Net resistance is given by

$R_{net}=R_1+R_2+R_3+R_4+R_5$

Substitute $\frac{1}{5}\Omega$ for $R_1$, $\frac{1}{5}\Omega$ for $R_2$, $\frac{1}{5}\Omega$ for $R_3$, $\frac{1}{5}\Omega$ for $R_4$ and $\frac{1}{5}\Omega$ for $R_5$ in net resistance expression.

$R_{net}=\frac{1}{5}\Omega +\frac{1}{5}\Omega +\frac{1}{5}\Omega +\frac{1}{5}\Omega +\frac{1}{5}\Omega =1\Omega$

Hence, Net resistance is $1\Omega$.