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Yes, I am asking for the relative positions of the image w.r.t. object using different lenses and mirrors...............and whether they are real, inverted, erect images, etc. and the sign convention of u and v in the lens makers formula, 1/f = 1/v - 1/u....................................
the sign convention that i use..
the side of the optical device where the ray is incident on the device>>object space
the other side of the optical device>> image space
measurements in the direction of image space>> positive
in the direction of object space>>negative
focal length of:
converging lens +ve
diverging lens -ve
concave mirror -ve
diverging mirror+ve
lens: 1/f =1/v - 1/u
mirror: 1/f =1/v + 1/u
To know whether inverted image or erect we can use two test rays.. one from object to optical centre which passes undeviated(in case of lens) or is reflected with the axis as its normal(in case of mirror).. the other ray parallel to the axis which then passes thru the focus orseems to emerge from it their intersection gives us the idea..
magnification> |m|=(|v|/n1)/(|u|/n2)... n1,n2 refractive indices of object & image space
Introduction to image formation by lenses: While attempting to draw the image formation by both convex and concave lenses, we need to know a few rules: * Any ray of light passing through the optical centre will pass undeviated from its original path. * Any ray of light moving parallel to the principal axis of the lens will pass through the focus of the lens. *Any ray of light passing through the focus of a lens will emerge parallel to the principal axis of the lens. Let us first see the image formation by a convex lens: *When the object is placed at infinity, the image is formed at the focus as shown below by the diagram. The image formed is point sized and is real and inverted. *When the object is placed between F and 2F, the image is formed beyond 2F. The image is enlarged and is real and inverted. *When the object is placed at 2F, the image is also formed at 2F. It is of the same size as that of the object and is again, real and inverted in nature. Object –at 2F *When the object is placed beyond 2F, the image is formed between F and 2F. The image at this stage is diminished and is real and inverted. Object – beyond 2F * When the object is placed between the optic centre, O and F, the image formed is on the same side as that of the object. In this situation, the image is virtual and erect and is enlarged. Object – between O and F Let us now see the image formation by a concave lens: Object – at infinity *When the object is placed at any point between infinity and the optic centre, the image is always formed between the optic centre, O and F. The image is diminished. Object – between infinity and the optic centre Image Formation by Convex Lens
Object – at infinity
Image – at F
Nature of image – real and inverted
Size of Image – point sized
Object – between F and 2F
Image – beyond 2F
Nature of image – real and inverted
Size of Image – enlarged 
Image –at 2F
Nature of image – real and inverted
Size of Image – same size as that of object
Image – between F and 2F
Nature of image – real and inverted
Size of Image – diminished
Image – On the same side as that of the object or behind the lens
Nature of image – virtual and erect
Size of Image – enlarged
Object – at F
Image – at infinity
Nature of image – real and inverted
Size of Image – highly enlarged
Image Formation by Concave Lens
Image – at F
Nature of image – virtual and erect
Size of Image – point sized
Image – between O and F
Nature of image – virtual and erect
Size of Image – diminished
Real image – If the two rays of light originated from a point, meets after refraction, such image is called the real image. Virtual image – If the two rays of light originated from a point, appears to meet after refraction, such image is called the virtual image. (i) If a ray of light passes from focus then after refraction it becomes parallel or appears to be parallel to the principal axis and vice versa. (ii) If a ray of light passes from optical centre remains passes without deviation. (i) When object placed at infinity The image is of point in size, formed at focus and nature is real. (ii) When object placed beyond 2F The image is diminished, formed between 2F and F and nature is real, inverted. (iii) When object placed at 2F The image is of same size, formed at 2F and nature is real and inverted. (iv) When object placed between F and 2F The image is enlarged, formed between 2F and infinity and nature is real, inverted. (v) When object placed at F The image is highly magnified, formed at infinity and nature is real, inverted. (vi) When object placed between F and O The image is enlarged, formed at the same side of the object and nature is virtual, erect. In case of concave lens, the image formed is always virtual, erect and small in size and always formed between focus and optical centre, irrespective to the position of the object. The convex lenses are used in simple microscope, compound microscope, refracting type telescopes, spectacles, laboratories etc. the concave lenses are used in spectacles, laboratories etc.Rules to Draw the Ray Diagrams of Images Formed by Lenses
Images Formed by Convex Lenses
Images Formed by Concave Lenses
Uses Image Formed by Lenses
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like can u explain " image with regard to the position of the object"
i do not understand ur ques..
u can know the position of image for a particular position of object for given optical device of a known focal length..
so are u asking for relative position of image w.r.t object??