Physics Question on Current electricity

Question

The radius of a thin wire is 0.16 mm. The area of cross-section of wire in $mm^2$ with correct number of significant figures is

Answer 1

Solution

Here, $R$ = 0.16 mm Hence, $A = \pi R^2$ $= \frac{22}{7} \times (0.16)^2 = 0.080457 \, mm^2$ Since radius has two significant figures so area also will have two significant figures. $\therefore \:\:\:\: A = 0.080\, mm^2$