2.3. Size of specimen

A microscope makes a specimen look larger than its actual size. You'll need to know how to calculate the magnification and actual size of the specimen.

This equation will be your best friend:

The standard unit for length is metre (m). 

Organelles are so small they are often measured in millimetres (mm).

• 1 metre = 1 000 millimetres (mm)
•              = 1 000 000 micrometers (µm)
•              = 1 000 000 000 nanometres (nm) - not required by syllabus

* make sure that the size of image and actual size of specimen are in the same unit (m/ mm/ µm), if not, your calculation will be incorrect!

Practice questions

[source: workbook]

For more past papers, click here.