Question

An object is 4 cm in front of a system of two converging lens’ each of focal length 10 cm and separated by distance of 20 cm. The image is :

	A.	Virtual and erect
	B.	Erect and the same size as the object
	C.	Reduced
	D.	Inverted and enlarged

Answer 1

given

object distance d0 = 4 cm

focal length f1 = f2 = 10 cm

separation distance d = 20 cm

from the realtion

1/d0+1/di = 1/f

image of first lens

di1 = 4*10/4-10 = -6.67 cm

final image distance di2 = 26.67*10/26.67-10 = 16 cm

magnification m = -16/4 = -4

inverted and enlarged image (answer)

it is a real image

option D