Question

The lowest resistance which can be obtained by connecting 10 resistors each of $\frac{1}{10}$ ohm is

• A. $\frac{1}{250}$ ohm
• B. $\frac{1}{200}ohm$
• C. $\frac{1}{100}ohm$
• D. $\frac{1}{10}ohm$

Answer 1

Answer: (C)

Lowest resistance will be obtained when connected in parallel
$\frac{1}{R_p}=\frac{1}{R_1}+\frac{1}{R_2}+\frac{1}{R_3}........\frac{1}{R_n}$
$\frac{1}{R_p}=\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}+\frac{1}{\frac{1}{10}}$
$\frac{1}{R_p}=100$
$\Rightarrow R_p=\frac{1}{100}$ ohm