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рдкреНрд░рд╢реНрди
Yesh find out F1 and F2 of symmetric convex lens experimentally then which conclusion is true.
рдкрд░реНрдпрд╛рдп
a) ЁЭР╣1 = ЁЭР╣2
b) ЁЭР╣1 > ЁЭР╣2
c) ЁЭР╣1 < ЁЭР╣2
d) ЁЭР╣1 ≠ ЁЭР╣2
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рдЙрддреНрддрд░
a) ЁЭР╣1 = ЁЭР╣2
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(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.
Study the given ray diagrams and select the correct statement from the following:
(A) Device X is a concave mirror and device Y is a convex lens, whose focal lengths are 20 cm and 25 cm respectively.
(B) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 10 cm and 25 cm respectively.
(C) Device X is a concave lens and device Y is a convex mirror, whose focal lengths are 20 cm and 25 cm respectively.
(D) Device X is a convex lens and device Y is a concave mirror, whose focal lengths are 20 cm and 25 cm respectively.
When a ray of light enters from one medium to another having different optical densities it bends. Why does this phenomenon occur?
Describe with the help of a ray diagram the nature, size and position of the image formed when an object is placed in front of a convex lens between focus and optical centre. State three characteristics of the image formed.
An object is placed at a distance equal to 2f in front of a convex lens. Draw a labelled ray diagram to show the formation of image. State two characteristics of the image formed.
You eye contains a convex lens. Why is it unwise to look at the sun?
State whether convex lens has a real focus or a virtual focus.
An object is placed f and 2f of a convex lens. Which of the following statements correctly describes its image?
(a) real, larger than the object
(b) erect, smaller than the object
(c) inverted, same size as object
(d) virtual, larger than the object
A converging lens forms the image of an object placed in front of it, beyond 2F2 of the lens. Draw a ray diagram to show the formation of the image.
A student places a 8.0 cm tall object 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. He obtains a sharp image of the object on a screen placed on the other side of the lens. What will be the nature (inverted, erect, magnified, diminished) of the image he obtains on a screen? Draw ray diagram to justify your answer.
For finding the focal length of a convex lens by obtaining the image of a distant object, one should use as the object.
(1) a well lit distant tree
(2) window grill in the class room
(3) any distant tree
(4) a lighted candle kept at the other end of the table.
For which position of the object does a convex lens form a virtual and erect image? Explain with the help of a ray diagram.
(a) What type of a lens can be used as a magnifying glass?
(b) Show by a ray diagram the formation of a real image by simple magnifying lens.
State the position of object, position of image, nature of image when: Convex lens is used as objective lens of astronomical telescope.
State the position of object, position of image, nature of image when: Convex lens is used as objective lens of photographic camera.
State the position of object, position of image, nature of image when: Convex lens is used as in searchlight.
Distinguish between:
Concave lens and Convex lens
