Page 1 :
. Position of the object beyond 2F:, Position of the image — between F & 2F, Nature of the image — real, inverted, diminished, , , , , , 7, dake A PRINCIPAL FOCUS, > = ‘praca cenTmE, convex Lens, concave lens “®, For more paper visi sunitutorial weebly.com Page jaz, , JSUNIL TUTORIAL, , , , Principal focus: The point Fin the figure for convex lens is actually the real, screen. Ths point is called the principal focus ofthe lens., , In the case of a concave lens, a vual image willbe formed at he point F whichis the prcipal focus of the, lens., , Focal length: The distance between the optical centre 0 and the focus F ofa lens is called the focal length, (oF)., , ‘8 Newton showed that a prism can produce a spectrum. He allowed a thin beam of ight ofall on a prism, in a dark room. Atte passing through the prism, the beam spits into its diferent colours. A spectrum was, ‘seen on a screen kept behind the prism., , HOTS Questions, , 41. No diference. The size ofthe image of any object formed on a plane |, ‘ofthe miro., , 2. Four identical mirror image letters H, 1, 0, X, , {3 Rear view mirrors are convex to have a useful field of view. They form a smaller image ofthe object, behind them. Since smaller objects appear farther away, the objects seen in the mirror look further away, than they realy are. I the driver does not realise this, he might turn or change lanes thinking that the car, behind is further away than it actualy i. This can result in an accident. The warning is there to remind the, dtiver ofthis potential problem., , converges parallel rays of ght after reflection so that they actually meet at the focus, ‘and form a real image. Therefore the focus is real, A convex miror diverges parallel rays of light after, reflection 60 that they appear to come from the focus. Therefore the focus is vial., , By the same logic a convex lens has areal focus (as it converges parallel rays), and a concave lens a, virtual focus (as it diverges parallel rays)., , 5. Glass lens wil have a greater focal length because it bends ight less than diamond. 6. In plane mirror,, all normals at the surface are parallel to each other., , 7. Infinite number of mages, as the image formed by one mirror becomes the object for the other miror, and so on., , , , age of the sun formed on a, , , , , , 4. Aconcave |, , , , , , , , For more paper vist junittoral weeby.com pay 3/3