Advertisements
Advertisements
प्रश्न
Why are the magnification properties of microscopes and telescopes defined in terms of the ratio of angles and not in terms of the ratio of sizes of objects and images?
उत्तर
Instruments like telescopes and microscopes deal with objects placed at different distances. Due to some physical factors, there is a relative change in heights not in the angle which the light emerging from them subtends on the lens. So, the magnification properties of instruments are defined in terms of the ratio of angles.
APPEARS IN
संबंधित प्रश्न
A biconvex lens with its two faces of equal radius of curvature R is made of a transparent medium of refractive index μ1. It is kept in contact with a medium of refractive index μ2 as shown in the figure.
(a) Find the equivalent focal length of the combination.
(b) Obtain the condition when this combination acts as a diverging lens.
(c) Draw the ray diagram for the case μ1 > (μ2 + 1) / 2, when the object is kept far away from the lens. Point out the nature of the image formed by the system.
A biconvex lens made of a transparent material of refractive index 1.5 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Give reason.
Define the magnifying power?
name the factors on which 'limit of resolution' depends ?
The size of an object as perceived by an eye depends primarily on
To increase the angular magnification of a simple microscope, one should increase ______.
A simple microscope has a magnifying power of 3.0 when the image is formed at the near point (25 cm) of a normal eye. (a) What is its focal length? (b) What will be its magnifying power if the image is formed at infinity?
A child has near point at 10 cm. What is the maximum angular magnification the child can have with a convex lens of focal length 10 cm?
Find the maximum magnifying power of a compound microscope having a 25 diopter lens as the objective, a 5 diopter lens as the eyepiece and the separation 30 cm between the two lenses. The least distance for clear vision is 25 cm.
The angular magnification of a system is less than one. Does it mean that the image formed is inverted?
A magnifying glass is a converging lens placed close to the eye. A farsighted person uses spectacles having converging lenses. Compare the functions of a converging lens used as a magnifying glass and as spectacles.
A person wears glasses of power − 2.5 D. Is the person farsighted or nearsighted? What is the far point of person without the glasses?
How does focal length of a convex lens change with increase in wavelength of incident light?
Magnification for spherical mirrors m is given by ______.
The focal length of the objective of a telescope is 60 cm. To obtain a magnification of 20, the focal length of the eye piece should be:
