Question

Tn the igurethe nages he focal le:Ste。fage le wewed on a scrm, and is i3,SMA.) qǐ.wtel ou ens ? 9.70 , ob +

Answer 1

Given 0 = 35 Cm h^' = 13.5 mm h = 9.70 mm we know from the definition of magnification m = -i/0 = h^'/h -i/0 = 13.5/9.7 -i/0 = 1.39 i = 1.93 times 0 \r\n = i = 1.39 times 35 i = 48.65 we know from Lens eqn 1/f = 1/i + 1/0 1/f = 1/48.65 + 1/35 f = 20.35 f = 20.4 cm Hence, focal length = 20.4 cm (option C)