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 speed of light in air is 3 × 108 m s-1. Calculate the speed of light in glass. The refractive index of glass is 1.5
The following diagram shows an object AB and a converging lens L with foci F1 and F2 State three characteristics of the image in relation to the object.
Define magnifying power of a simple microscope. How can it be increased?
What information we seek by the linear magnification of the image when it is positive or negative?
Name the lens for which magnification can be 1. For what position of the object will the magnification be 1?
A convex lens produces on a screen an image twice the size of the object. If the position of image and object be interchanged, what will be the magnification then?
An object is placed in front of a lens between its optical centre and the focus and forms a virtual, erect, and diminished image. Draw a ray diagram to show the formation of the image with the above-stated characteristics.
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.
What is a simple microscope or a magnifying glass? Draw a ray diagram to show its function.
An object AB is placed between 2F1 and F1 on the principal axis of a convex lens as shown in the diagram. Copy the diagram and using three rays starting from point A, obtain the image of the object formed by the lens.
