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प्रश्न
The image obtained while finding the focal length of convex lens is ....................
पर्याय
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
An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed.
Write one condition where it does not bend when entering a medium of different optical density.
A beam of light travelling in air is incident of water. Draw a ray-diagram indicating the change in its path in water.
A ray of light travelling in air is incident on a parallel-sided glass slab (or rectangular glass slab). Draw a ray-diagram indicating the change in its path in glass.
Draw a labelled ray diagram to show how a ray of light is refracted when it passes:
from air into an optically denser medium.
Draw a labelled ray diagram to show how a ray of light is refracted when it passes:
from an optically denser medium into air.
The diagram given alongside shows a ray of light entering a rectangular block of glass.
(a) Copy the diagram and draw the normal at the point of entry.
(b) Draw the approximate path of the ray of light through the glass block and out of the other side.
Define principal axis, principal focus and focal length of a convex lens.
With the help of a labelled diagram explain how a convex lens converges a beam of parallel light rays. Mark the principal axis, optical centre, principal focus and focal length of the convex lens on the diagram.
A light ray does not bend at the boundary in passing from one medium to the other medium if the angle of incident is:
For which position of the object does a convex lens form a virtual and erect image? Explain with the help of a ray diagram.
State two applications of a convex lens.
An object 4.0 cm in size, is placed 25.0 cm in front of a concave mirror of focal length 15.0 cm.
(i) At what distance from the mirror should a screen be placed in order to obtain a sharp image?
(ii) Find the size of the image.
(iii) Draw a ray diagram to show the formation of the image in this case.
What happens to the image formed by a convex lens if its lower part is blackened?
Write the name.
The lens used in simple microscope.
Observe the given figure and answer the following questions.
- Where is the above type of lens construction used?
- What type of image is formed by an objective lens?
- What happens instead of placing at Fo if the object is placed in between O and Fo?
