Advertisements
Advertisements
प्रश्न
A lens forms an upright and diminished image of an object, irrespective of its position. What kind of lens is this? Draw an outline ray diagram to show the formation of the image. State the position and one more characteristic of the image.
Advertisements
उत्तर
A concave (or diverging) lens forms an upright and diminished image of an object irrespective of its position.
The outline ray diagram showing the formation of the image is given in figure. For the object AB, the image is A’B’.
The image is formed between optical centre O and focus F, in front of the lens.
The image is virtual.
संबंधित प्रश्न
You have two lenses A and B of focal lengths +10 cm and –10 cm, respectively. State the nature and power of each lens. Which of the two lenses will form a virtual and magnified image of an object placed 8 cm from the lens? Draw a ray diagram to justify your answer
The focal length of a convex lens is 25 cm. What is its power?
A diverging lens has focal length of 3 cm. Calculate the power.
The optician's prescription for a spectacle lens is marked +0.5 D. What is the:
(a) nature of spectacle lens?
(b) focal length of spectacle lens?
A lens has a focal length of, −10 cm. What is the power of the lens and what is its nature?
Mohan obtained a sharp inverted image of a distant tree on the screen placed behind the lens. He then moved the screen and tried to look through the lens in the direction of the object. He would see:
(1) a blurred image on the wall of the laboratory.
(2) an erect image of the tree on the lens.
(3) no image as the screen has been removed
(4) an inverted image of the tree at the focus of the lens.
A symmetric double convex lens in cut in two equal parts by a plane perpendicular to the principal axis. If the power of the original lens was 4 D, the power a cut-lens will be
A convex lens is a converging lens whose focal length and power are both:
A greater numerical value of the power of a lens means:
The power of a lens of focal length \[f = 0.5\,m\] is:
