Question

When viewing a specimen with a compound microscope, which objective lens should you start with?

A) Low-power objective
B) High-power objective
C) Oil immersion objective
D) Medium-power objective

Answer 1

Start with the low-power objective lens when using a compound microscope; it allows you to locate the specimen easily due to its larger field of view and working distance. After focusing, you can switch to higher magnification lenses.

Step-by-step explanation:

When using a compound microscope, you should start with the low-power objective lens. This lens has a lower magnification level, which allows for a larger field of view and greater working distance, making it easier to initially locate the specimen. Once you have centered and focused on the specimen with the low-power objective, you can switch to a higher magnification like the medium-power or high-power objective lenses, and finally to the oil immersion objective if necessary. Microscopes are designed to be parfocal, which means that after focusing at a lower magnification, only minimal adjustments are required to achieve focus when switching to a higher magnification lens.