Question

A 6 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 16 cm. The distance of the object from the lens is 9 cm. Using the lens formula
1) Find the position
2) size
3) Nature of the image formed.

Answer 1

Answer:

height of object = 6cm

focal length of convex lens, f = +15cm

object distance from the lens, u = -10cm

from lens maker formula,

1/v - 1/u = 1/f

1/v - 1/-10 = 1/15

or, 1/v = 1/15 - 1/10

or, 1/v = 2/30 - 3/30 = -1/30

or, v = -30cm

hence, position of image is 30cm aways from the lens.

magnification, m = v/u

or, height of image/height of object = v/u

or, height of image/6cm = (-30cm)/(-10cm)

or, height of image = 18cm

hence, height of image is 18cm ( larger than object )

so, position of image => 30cm

size of image => 18cm

nature of image => real and enlarged