(i) At what distance should the lens be held from the card sheet in order to view the squares distinctly with the maximum possible magnifying power ? (ii) What is the magnification in this case ? (iii) Is the magnification equal to magnifying power in this case ? Explain.
Text Solution
Verified by Experts
(i) Here, `v = - 25 cm, f = 10 cm, u = ?` As `(1)/(v) - (1)/(u) = (1)/(f) :. (1)/(u) = (1)/(v) - (1)/(f) = (1)/(-25) - (1)/(10) = (-2 - 5)/(50)` `u = (-50)/(7) = - 7.14 cm` (ii) Magnification, `m = (v)/(|u|) = (25)/(7.14) = 3.5` (iii) Magnifying power `= (d)/(u) = (25)/(7.14) = 3.5` Yes, Magnification and magnifying power in this case are equal, because image is formed at the least distance of distanct vision.
Topper's Solved these Questions
OPTICS
PRADEEP|Exercise Very short answer question|5 Videos
OPTICS
PRADEEP|Exercise very short answer questions|1 Videos
A cardsheet divided into squares each of size 1 mm^(2) is being viewed at a distance of 9 cm through a magnifying glass (a conerging lens of focal length 10 cm ) held close to the eye. (a) What is the magnification produced by the lenas ? How much is the area of each square to the virtual image ? (b) What is the angular magnification (magnifying power) of the lens ? ( c) Is the magnification in (a) equal to the magnifying power in (b) ? Explain
At what distance should an object be placed from a convex lens of focal length 18 cm to obain an image at 24 cm from it one the other side? What will be the magnification produced in this case?
At what distance should an object be placed from a lens of focal length 25 cm to obtain an image on a screen placed at a distance of 50 cm from the lens ? What will be the magnification produced in this case?
A man with normal near- point (25c m) reads a book with small print using a magnifying glass L a thin convex lens of focal length 5 cm. (i) What is the closest and the farthest distance at which he can read the book when viewing thorugh the magnifying glass ? (ii) What is the maximum and the minimum angular magnification (magnifying power) possible using the above simple microscope ?
A graph sheet divided into squares each of size \mm 2 is kept at a distance of 7cm from a magnifying glass of focal length of 8cm. The graph sheet is viewed through the magnifying lens keeping the eye close to the lens. Find (i) the magnification produced by the lens, (ii) the '(irea of each square in the image formed (iii) the magnifying power of the magnifying lens. Why is the magnification found in (i) different from the magnifying power?
A man with normal near point (25 cm) reads a book with small print using a magnifying glass : a thin convex lens of focal length 5 cm . (a) What are the closest and the farthest distances at which he can read the book when viewing through the magnifying glass ? (b) What is the maximum and the minimum angular magnifications (magnifying powers) possible using the above simple microscope ?
