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REFLECTED LIGHT CAN BE REFLECTED AGAIN pe, ai asleae ertle incident on another plane mirror, nen anit., ie ; i » incident rays for, a vie case, the reflected rays of the first plane mirror become ;, in. nv this cae theinetDogied Faye © ang ne also takes place according to the laws, vhich reflected light is reflected again is q, , , , If the ravs of light reflected by a plane mirror are, ravs are reflected age, { plane mirror The further reflection from second pl, mn of Inght. An optical instrument (or device) tn t, , *, ', , BEC OTIC j, of reflect, periscope. We will now describe a periscope. ,, , A periscope is a long, tubular device through which, a person can see objects that aré out of the direct line of, ives us a higher view than normal. For, , sight A PETIScopy 21, by using a periscope, we can see the objects on, , , , , , “Object to, .. aa nts A areal irearhiic —— nave be seen ‘, the other side of a high wall which cannot be seen by us (Here a (rae) Es ale, , directly The periscope makes use of two plane mirrors to, e over the top of things. Actually, a periscope works on, he reflection of light from two plane mirrors arranged, , the reflection of light from two ple rrors arrang High wall—>, , crampic, , , , , , , , , , , , parallel to one another, A periscope consists of a long (Obstacle), tube T having two plane mirrors M, and M, fitted at its, two ends (as shown in Figure 12). The two plane mirrors, fitted in such a way that they are parallel to one, wr and their reflecting surfaces face each other. Each ie coe Oi rs, plane mirror, however, makes an angle of 45° with the = pie, aide of the tube (see Figure 12). There are two holes in the Figure 12. Diagram to show the working of a periscope, «tube one hole is in front of the top mirror M, and the other hole is in front of the bottom mirror, re, ', We will now describe the working of a periscope. Suppose there is a tree behind a high wall which, a ‘ woe directly (see Figure 12). We can, however, see this tree by using a periscope. This can be done, muows The upper hole of periscope is turned towards the object to be seen (here a tree) so that the top , 7 eats — = piject. “ ° - into the periscope from the bottom hole in front of lower mirror Me, dome ards . : : : = ~ One fall on the plane mirror M,. Mirror M, reflects these rays of light light tewards the . ; Fale murror Mi, ee Figure F The nierror M, then reflects the reflected raysot, ete person looking into the periscope through the lower hole. Since the light rays.