Biology 9700/12 — October/November 2022

The diagram shows a stage micrometer, with divisions $0.10\text{ mm}$ apart, viewed through an eyepiece containing a graticule.

The area of the field of view of the microscope can be calculated using this formula.

A student calculated the area of the field of view of the microscope using the information provided and a value for $\pi$ of $3.142$.

Which answer has been rounded correctly to an appropriate number of significant figures?

Options

A   $0.04909\text{ mm}^2$
B   $5 \times 10^{-2}\text{ mm}^2$
C   $4.909 \times 10^4\ \mu\text{m}^2$
D   $4.91 \times 10^4\ \mu\text{m}^2$