Question

A thin cylindrical wire has a length of $21.7\text{cm}$ and radius of $0.46\text{mm}$. The volume of the thin wire to the correct significant figures is

• A. $0.1{\text{cm}}^3$
• B. $0.14{\text{cm}}^3$
• C. $0.144{\text{cm}}^3$
• D. $0.1443{\text{cm}}^3$

Answer 1

The correct option is B $0.14{\text{cm}}^3$

Given,
$r=0.46\text{mm}=0.046\text{cm}$
$l=21.7\text{cm}$
We know the volume of the cylinder,
$V=\pi r^{2}l$
$\Rightarrow V=\frac{22}{7}\times (0.046{)}^2\times 21.7$
$\Rightarrow V=0.1443{\text{cm}}^3$
On applying the rule of significant figures for multiplication, we get, $V=0.14{\text{cm}}^3$