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प्रश्न
The image obtained while finding the focal length of convex lens is ....................
विकल्प
a) a real and erect.
b) virtual and erect.
c) real and inverted.
d) virtual and inverted.
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उत्तर
c) real and inverted.
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संबंधित प्रश्न
A student has obtained a magnified image of a flame on a screen using a convex lens. To draw the corresponding ray diagram to show the image formation, which of the following two rays whose paths after refraction are shown, should he select ?
(A) I and II
(B) II and III
(C) III and IV
(D) I and III
Which of the following lenses would you prefer to use while reading small letters found in a dictionary?
Complete the following table:
| Instrument | Number of Convex Lenses |
Use |
| Simple Microscope | .............. | .............. |
| Compound Microscope | .............. | .............. |
| Telescope | .............. | .............. |
Draw a labelled ray diagram to show how a ray of light is refracted when it passes:
from air into an optically denser medium.
A 1 cm high object is placed at a distance of 2f from a convex lens. What is the height of the image formed?
Describe with the help of a ray diagram the nature, size and position of the image formed when an object is placed at infinity (considerable distance) in front of a convex lens. State three characteristics of the image so formed.
How could you find the focal length of a convex lens rapidly but approximately?
State whether convex lens has a real focus or a virtual focus.
A convex lens of focal length 8 cm forms a real image of the same size as the object. The distance between object and its image will be:
(a) 8 cm
(b) 16 cm
(c) 24 cm
(d) 32 cm
An object 2 cm tall is placed on the axis of a convex lens of focal length 5 cm at a distance of 10 m from the optical centre of the lens. Find the nature, position and size of the image formed. Which case of image formation by convex lenses is illustrated by this example?
A student did an experiment with a convex lens. He put an object at different distances 25 cm, 30 cm, 40 cm, 60 cm and 120 cm from the lens. In each case he measured the distance of the image from the lens. His results were 100 cm, 24 cm, 60 cm, 30 cm and 40 cm, respectively. Unfortunately his results are written in wrong order.
What would be the image distance if the object distance was 90 cm?
The diagram alongside shows the refraction of a ray of light from sir to a liquid.
(a) write the values of (i) angle of incidence, (ii) angle of refraction.
(b) use snell’s law to find the refractive index of liquid with respect to air.
In figure , name the ray which represents the correct path of light while emerging out through
a glass block.
Out of the five incident rays shown in the figure find the three rays that are obeying the laws of refraction and may be used for locating the position of image formed by a convex lens:
(A) 1, 2 and 3
(B) 2, 3 and 4
(C) 3, 4 and 5
(D) 1, 2 and 4
Distinguish between:
Concave lens and Convex lens
If an object is placed in front of a convex lens beyond 2F1, then what will be the position, relative size, and nature of an image which is formed? Explain with a ray diagram.
Can a normal convex lens behave like a concave lens and vice-versa?
Object at 2F1 of a convex lens : Image at 2F2 : : Object at F1 : _______
Which of the following statements is true?
Distinguish between:
Concave lens and Convex lens
