Advertisements
Advertisements
Question
The magnification by a lens is -3. Name the lens and state how are u and v related?
Advertisements
Solution
The negative value of magnification suggests that image is real and inverted. The magnitude of magnification is greater than 1 which means image is enlarged. Therefore the lens should be convex lens.
Relation between u and v is given by
m = `"v"/"u"`
`-3 = "v"/-"u"`
v = 3 u
This shows that image distance is 3 times that of object distance.
RELATED QUESTIONS
The following diagram shows an object AB and a converging lens L with foci F1 and F2. Draw two rays from the object AB and complete the diagram to locate the position of the image CD. Also mark on the diagram the position of eye from where the image can be viewed.
A lens forms an erect, magnified and virtual image of an object.Draw a ray diagram to show the formation of image.
An object is placed at a distance of 20 cm in front of a concave lens of focal length 20 cm. find: the magnification of image.
Will the image formed by a magnifying glass be real or virtual?
Define magnification produced by a lens. State its unit.
Name the lens for which magnification can be 1. For what position of the object will the magnification be 1?
Name the lens for which magnification is always less than 1.
Show with the help of a ray diagram, the path of the ray when incident normally on the first surface of the glass block, through the block and the liquid.
Copy and complete the following ray diagram.
(i) Draw a ray diagram to show how the lens can be used as a ‘magnifying glass’? State the nature of the lens.
(ii) In what respect does the image in (i) above different from the image formed by a concave lens?
