Question

The radius of a thin wire is 0.16 mm. The area of cross-section taking significant figure into consideration in square millimeters is?

• A. 0.0804
• B. 0.08
• C. 0.08
• D. 0.080384

Answer 1

The correct option is B 0.08

$Area=\pi r^2=\pi \times {0.16}^2=0.080384$

Since final answer should contain same number of significant figures as in question.

0.16 has 2 significant digits

So, answer should also have 2 significant digits.

So, the answer is $0.080m{m}^2$