Question

an object 4cm tall is kept on the principal axis of a converging lens focal length 12cm find the position nature and size of the image formed if the object is at 18 cm from the lens also find
the height of the image​

Answer 1

Answer:

Focal length = 12 cm = f

Distance of object lens = u = -18 cm

Object height = h = 10 cm

Convex lens :

\frac{1}{v}-\frac{1}{u}=\frac{1}{f}

\frac{1}{v}=\frac{1}{f} + \frac{1}{u}

\frac{1}{v}=\frac{1}{12} + \frac{1}{(-18)}

v = 36cm

m = \frac{v}{u}=\frac{h'}{h}

m = \frac{36}{-18}=\frac{h'}{10}

h' = -20cm (size of the image)

Nature of the image is Real and inverted.

Explanation: