A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)
- Increase the refractive index of the medium between the object and objective lens
- Decrease the diameter of the objective lens
- Increase the wave length of the light
- Decrease the focal length of the eye piece.
The Correct Option is A
Solution and Explanation
The resolving power (\(P\)) of a microscope is given by: \[ P = \frac{2 \mu \sin \theta}{1.22 \lambda}, \] where: \(\mu\) is the refractive index of the medium, \item \(\lambda\) is the wavelength of light.
To improve resolving power: Increasing \(\mu\) (refractive index) improves \(P\), Decreasing \(\lambda\) also increases \(P\).
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Concepts Used:
Optical instruments
A device that processes light waves (or photons), either to enhance an image for viewing or to analyze and determine its characteristic properties is called an optical instrument (or "optic" for short).
Applications of Optical Instruments:
- Microscope - It is one of the most extensively used optical instruments comprised of only one lens or combination of the lenses for magnifying and inspecting bodies that are too small to be seen in detail by clear eyes. Earlier microscopes had only one lens, and are, therefore, called simple microscopes, but the present microscopes are accessible with at least two lenses and thereby, termed a compound microscope.
- Telescope - It is another remarkable optical instrument. It makes distant objects emerge nearer by using an arrangement of lenses or lenses and curved mirrors that is used to observe the objects by absorption, emission, and reflection of their electromagnetic radiation to furnish a magnified image. As they are used to view objects that are far away, they include at least two lenses.