Question

An object 5 cm in length is placed at a distance of 20 cm in front of a convex mirror of radius of curvature of 30 cm. The distance of image, its size and nature will be
(3 Points)
a)8.57 cm ,2.14 cm, virtual and erect
b)4.54 cm,1.22 cm, real and inverted
c)7.12 cm, 3.24 cm, real and inverted
d)6.91 cm, 3.54 cm, virtual and erect​

Answer 1

Answer:

A. 8.57CM , 2.14CM , VIRTUAL AND ERECT

Explanation:

Radius of curvature (R) = 30 cm

f = R/2 = 30/2 = 15 cm

u = -20 cm,

h= 5 cm.

1/v +1/u = 1/f

1/v = 1/15+ 1/20 = 7/60

v = 60/7 =  8. 57 = 8.6 cm.

Image is virtual and erect and formed behind the mirror.

hi/h0= v/u

hi/5= 8.6/20

hi = 2.15 = 2.2 cm.

Size of image is 2.2 cm.