Question

The width of typical human hair strand is 0.012 cm which is equal to .

• A. $12\mu m$
• B. $120\mu m$
• C. $120nm$
• D. $1200nm$

Answer 1

The correct option is B $120\mu m$

Given:
The width of a typical human hair strand, $w=0.012cm$
$1m=100cm$
Also $1\mu m={10}^{-6}m$, i.e. one millionth of a metre.
$⟹1\mu m={10}^{-6}\times 100cm$
$={10}^{-4}cm$
So, $1cm={10}^4\mu m$
Hence, $w=0.012cm=0.012\times {10}^4\mu m$
$⟹w=120\mu m$