How is total magnification on a compound microscope calculated?

• A. Multiply the eyepiece power by the objective power
• B. Add the eyepiece power to the objective power
• C. Subtract the objective power from the eyepiece power
• D. Divide the eyepiece power by the objective power

Answer: (A)

Total magnification on a compound microscope is found by multiplying the magnification of the eyepiece by the magnification of the objective. The eyepiece enlarges the image that the objective forms, so the overall enlargement is the product of the two magnifications. For example, with an eyepiece of 10x and an objective of 40x, the total magnification is 400x. Adding, subtracting, or dividing the two magnifications doesn’t describe how two lenses in sequence amplify the image—the magnifications combine multiplicatively.