Question

an object of height 120 centimetre is standing at a distance of 50 cm from the mirror then the image distance from the object will be
a. 360cm
b.120 cm
c. 240cm
d.50cm​

Answer 1

Explanation:

radius of curvature= focal length/2

and radius of curvature = 120

so the focal length = 60

and magnification =4

and formula of magnification is -v/u

so -v/u=4 -

so, v in terms of u is -4u

so putting value in mirror formula

1/v+1/u=1/f

we have found the value of v and f

so 1/-4u+1/u=1/60

-1+4/4u=1/60

so 4u/ 3 =60

u=45

so value of v can be found by putting the value of u in formula of magnification

so, v=-180

so -180 means the image will be formed inverted and at a distance of 180 from the mirror