Question

A 1.5 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 15 cm distance of object from the lens is 20cm use lens formula to find the nature and size of image

Answer 1

Answer:

Virtual and exact date

Answer 2

Explanation:

Given : height of object (ho) 1.5cm

focal length 15cm

object distance - 20cm

convex lens

To find nature

size

proof : by lens formula

1/f=1/v-1/u

1/15 = 1/v- (1/-20)

1/15 +1/20 =1/v

take lcm as 60

4+3/60=1/v

7/60 =1/v

7v =60

v =60/7

v = 8.57cm

NATURE IMAGE FORMED IS Virtual and erect .

Size = hi/ho=v/u

hi/1.5 =60/7/-20

hi/ 1.5 = - 60/ 140

hi/1.5= -6/14

hi/1.5 = -3/7

7hi = -4.5

hi = -4.5 /7