Question

An object of height 5cm is placed perpendicular to the principal axis of a concave lens of focal length 10 cm. If the distance of the object from the optical centre of the lens is 20 cm determine the position nature and size of the image formed

Answer 1

Dear Student

Height of object= 5cm
f= -10cm
u = -20cm

Using lens formula:
1/v-1/u = 1/f
1/v-(-1/20)=(-1/10)
v = -20/3 cm
So, Image distance= -6.67cm
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Magnification= v/u = height of image/height of object
or, (-20/3)/20=height of image/5
Height of image = 1.66cm

Regards