Question

Particle size range of optical microscopy

• A. 500–1000 \mu
• B. 0.001–0.1 \mu
• C. 200–500 \mu
• D. 0.5–1.50 \mu

Hint:

The resolving power of optical microscopes limits particle size measurement to about 0.2 μm and above, making it suitable for microparticles but not nanoparticles.

Answer 1

The Correct Option is D

Optical microscopy (light microscopy) uses visible light and lenses to magnify particles. Its resolution limit is governed by the wavelength of visible light, typically around 0.2 micrometers (\mu). - The smallest particle size that can be effectively visualized and measured using optical microscopy generally ranges from about 0.5 μm to 1.5 \mu
- Particles larger than this range can be easily seen, but optical microscopy is most accurate and commonly used for particles within this micrometer range.
- Particles smaller than 0.2 \mu cannot be resolved clearly by optical microscopes and require electron microscopy techniques such as SEM or TEM for characterization.
- The options with very large sizes like 500–1000 μm correspond to sizes easily visible to the naked eye or low magnification and are not the typical particle size range used for optical microscopy particle size analysis.
Hence, the correct particle size range for optical microscopy is 0.5–1.50 \mu.