Question

Two concave lenses, each with ƒ = −15 cm, are separated by 7.5 cm. An object is placed 25 cm in front of one of the lenses. Find (a) the location and (b) the magnification of the final image produced by this lens combination.

How would I solve this using ray tracing?

Answer 1

Sol Image formed by first lens So lens for the first 1b = -25cm — = + + So _ 4 25 cm C: 7.5 che t> -14 43 f = -15 cm cm J = -($tis) 25415 = -52943 2541843 NE; -cm - final image distance initial position Sody the . of for first the lins second is lens

So for the lens the second fi - 15 cm U, 75 to t - Things clar ca va 70 = 5.76em final will be formed at 5-76cm So [b] magnification of combined lens m = magnification of first lens Me = magnification of second long M = mima 913 oy -75 x25

-Capo - 5.76 x 8 -75 mixom, So ma m= mixm2 5.76 x 5.7688 78 oxast I m = 0:230 magni fication = +0.230 m is positive so emage will de crect.