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प्रश्न
A convex lens forms an image of an object equal to the size of the object. Draw a diagram to illustrate it.
उत्तर
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संबंधित प्रश्न
(a) Draw a ray diagram to show the formation of an image by a convex lens when an object is placed in front of the lens between its optical centre and principal focus.
(b) In the above ray diagram, mark the object distance (u) and the image distance (v) with their proper signs (+ve or –ve as per the new Cartesian sign convention) and state how these distances are related to the focal length (f) of the convex lens in this case.
(c) Find the power of a convex lens which forms a real and inverted image of magnification –1 of an object placed at a distance of 20 cm from its optical centre.
A beam of light travelling in a rectangular glass slab emerges into air. Draw a ray-diagram indicating the change in its path.
A ray of light travelling in water emerges into air. Draw a ray-diagram indicating the change in its path.
You eye contains a convex lens. Why is it unwise to look at the sun?
A burning candle whose flame is 1.5 cm tall is placed at a certain distance in front of a convex lens. An image of candle flame is received on a white screen kept behind the lens. The image of flame also measures 1.5 cm. If f is the focal length of convex lens, the candle is placed:
(a) at f
(b) between f and 2f
(c) at 2f
(d) beyond 2f
Find the nature, position and magnification of the images formed by a convex lens of focal length 0.20 m if the object is placed at a distance of:
0.15 m
An object is placed perpendicular to the principal axis of a convex lens of focal length 20 cm. The distance of the object from the lens is 30 cm. Find (i) the position (ii) the magnification and (iii) the nature of the image formed.
How will you determine the focal length of a convex lens by the plane mirror method?
Diagram shows an object AB placed on the principal axis B of a convex lens placed in air. F1 and F2 are the two foci of the lens.
(i) Copy the diagram:
Draw a ray of light starting from B and passing through O. Show the same ray after refraction by the lens. Draw another ray from B which passes through F2 after refraction by the lens. Locate the final image
(ii) Is the image real or virtual?
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?
