Question

Resolving powers of the human eye, compound microscope and the electron microscope are ............. respectively.

• A. $100\mu$m, $0.25\mu$m and $10A^o$
• B. $100\mu$m, $100$nm and $100A^o$
• C. $1$mm, $10\mu$m and $100$nm
• D. $1$mm, $0.5\mu$m and $1A^o$

Answer 1

The correct option is A $100\mu$m, $0.25\mu$m and $10A^o$

The resolution of a typical unaided human eye is about 100 µm. Using a microscope decreases the resolution to distances as short as 0.1 µm. Resolution is a property of the eye. Resolving power is the ability of a lens to show two adjacent objects as discrete. A compound microscope uses two lenses at once to magnify the image of a specimen. The ocular lens is found in the eyepiece while the objective lens is found in the revolving nosepiece. The resolving power is the capacity of an instrument to resolve two points which are close together. The resolving power of a compound microscope is 0.25um. The resolving powers of ordinary electron microscopes are 1 nanometer (above the limit because construction details determine resolving power), a value which can be pushed to 0.1 nanometers or 10A.

Hence the correct answer is (A)