$10$ wires (same length, same area, same material) are connected in parallel and each has $1\Omega$ resistance, then the equivalent resistance will be

When $n$ no. of resistances are connected parallelly then

$\dfrac{1}{R_{eq} } = \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + \dfrac{1}{R} + ................$

$\dfrac{1}{R_{eq} } = \frac{n}{R}$

$\Rightarrow$ $R_{eq} = \dfrac{R}{n}$

$\Rightarrow$ $R_{eq}=\dfrac {R}{n}=\dfrac {1}{10}=0.1\Omega$