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प्रश्न
Which causes more bending (or more refraction) of light rays passing through it : a convex lens of long focal length or a convex lens of short focal length?
उत्तर
The bending of light by a convex lens depends on the power of the lens. The more the power, the more the light bends. A convex lens having a short focal length will have more power and hence, a higher refraction.
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संबंधित प्रश्न
A student places a candle flame at a distance of about 60 cm from a convex lens of focal length 10 cm and focuses the image of the flame on a screen. After that he gradually moves the flame towards the lens and each time focuses the image on the screen.
(a) In which direction-toward or away from the lens, does he move the screen to focus the image?
(b) How does the size of the image change?
(c) How does the intensity of the image change as the flame moves towards the lens?
(d) Approximately for what distance between the flame and the lens, the image formed on the screen is inverted and of the same size?
Draw a labelled ray diagram to show how a ray of light is refracted when it passes:
from air into an optically denser medium.
Define principal axis, principal focus and focal length of a convex lens.
What kind of lens can form:
am erect diminished image?
Study the diagram below.
what are the points O, O’ called?
i. Which type of microscope has the arrangement of lenses shown in the adjoining figure?
ii. Label the figure correctly.
iii. Write the working of this microscope.
iv. Where does this microscope used?
v. Suggest a way to increase the efficiency of this microscope.
The focal length of a lens is positive. In this case, state the kind of lens.
Answer the following question.
List four precautions which a student should observe while determining the focal length of a given convex lens by obtaining an image of a distant object on a screen.
What is the difference between a double convex and a bi-convex lens?
How will you decide whether a given piece of glass is a concave lens, convex lens, or a plane glass plate?
