This is going to be a short blog. The most important thing for a biologist, and a science student is knowing how to calculate magnification. It is crucial for a practical exam and practical tests. This is even useful for those who are in the alternate to practical section. Calculating Magnification is necessary for questions which have pictures or diagrams in it.
If you have been given magnification in an exam or in case of a practical test, you know the magnification from the microscope and draw an exact copy of the structure you see before your eyes whether practically or on an exam paper (you will be asked to draw a diagram) you can calculate the magnification of your drawing by the use of a normal meter-rule, half meter-rule, or a normal scale. With the measuring apparatus you should measure the length of your drawing and the length of the picture given in exam, divide these two numbers and multiply them with the given magnification to find the magnification of your drawing. The formula is as follows:
magnification of drawing= magnification of photograph (given) × length of drawing ÷ length of photograph
Sometimes the exam question would demand the magnification of your drawing but would not give the magnification of the photograph in that case we would have to calculate the length of the photograph and the drawing in micrometer (µm). To know the length of an object in micrometer, you should know that 1 mm is equal to 1000 µm. In this case the formula will be:
Magnification of Drawing= length of drawing ÷ length of photograph
These two formulas are necessary to learn and use to be successful in calculating magnification in your biology exam and even in practical tests