Using a compound microscope, you want to view a plant cell under a magnification of 100x. Given that your eyepiece has a magnification of 10x, which objective should you use to achieve your desired magnification?

Using a compound microscope, you want to view a plant cell under a magnification of 100x. Given that your eyepiece has a magnification of 10x, which objective should you use to achieve your desired magnification?

• A. 10x
• B. 90x
• C. 100x
• D. 110x

Answer: (A)

Total magnification in a compound microscope is the product of the eyepiece magnification and the objective magnification. To reach 100x with an eyepiece that has 10x magnification, you need an objective of 100 ÷ 10 = 10x. So the 10x objective gives the desired 100x total magnification (10x eyepiece times 10x objective). A 90x objective would give 900x, a 100x objective would give 1000x, and a 110x objective would give 1100x—far from the target. The 10x objective is the correct match.

Total magnification in a compound microscope is the product of the eyepiece magnification and the objective magnification. To reach 100x with an eyepiece that has 10x magnification, you need an objective of 100 ÷ 10 = 10x. So the 10x objective gives the desired 100x total magnification (10x eyepiece times 10x objective). A 90x objective would give 900x, a 100x objective would give 1000x, and a 110x objective would give 1100x—far from the target. The 10x objective is the correct match.