Question

Why cedar wood oil is used for oil immersion microscope

Answer 1

Answer: When light passes from a material of one refractive index to another (for example: from glass to air), it bends. In the space between the microscope objective lens and the slide (where air is), light is refracted, the light scatters and it is lost. The refractive index of air is approximately 1.0, while the refractive index of glass is approximately 1.5. When light passes through both glass and air it is refracted. Light of different wavelengths bends at different angles, so as objects are magnified more, images become less distinct. Basically when using lower magnification microscope objective lenses (4x, 10x, 40x) the light refraction is not usually noticeable. However, once you use the 100x objective lens, the light refraction when using a dry lens is noticeable. If you can reduce the amount of light refraction, more light passing through the microscope slide will be directed through the very narrow diameter of a higher power objective lens. In microscopy, more light = clear and crisp images. By placing a substance such as immersion oil with a refractive index equal to that of the glass slide in the space filled with air, more light is directed through the objective and a clearer image is observed.

Explanation:

Answer 2

Cedarwood oil is used as it has a tendency to harden and can cause lens damage if not removed after use

Explanation:

1. When utilising oil targets, it's critical to remember to use suitable immersion oil. Use just the oil that the objective maker recommends.
2. For many years, cedarwood oil was the standard immersion oil (and is still commercially available).
3. Although this oil has a refractive index of 1.516, it has a propensity to harden and, if not removed after usage, might cause lens damage. Furthermore, this oil absorbs blue wavelength and ultraviolet light, and it might yellow with time.