Question

a 2 cm tall object is placed at principle axis of a concave mirroi at distance of 12 if real image is 5cm tall then find position of image and f

Answer 1

Hey... I think this can be ur answer!!

Given :
h =2cm
u = - 12cm
h' = - 5cm

Now,
h'/h = - v/u
-5/2 = - v/-12
60/2=-v
v = - 30cm

1/f = 1/v + 1/u
=1/ - 30 + 1/ - 12
=1/-30 - 1/12
=-2-5/60
=-7/60
=-60/7
=-8.57cm

Answer 2

★Ello★

here is your answer :-

real image is formed , so magnification will be negative

now , given =>

h° = 2cm

U = -12

m = image distance / object distance

=>

[ m = f / f -u ] ( special trick for finding magnification quickly ) and it also helps you to find other units like. , image distance , object distance ,.

- 5 / 2 = m

m = f / f - u

-5 /2 = - f / - f + 12

on calculation we get , F = 8 .5

now ,

m = - V / u



=> - 5 / 2 = - v / 12

v = 30



hope it helps you dear !!!

$thanks$