Question

An object is placed at a distance of 10 cm from a convex mirror of focal length 5 cm.(1) Find the position nature and size of the imsge form.

Answer 1

With the standard cartesian sign conventions we can classify the units with sign :-

u=−10 cm

R=+30 cm so, f=+15 cm

ho=5 cm

Now, by mirror formula and some calculations we can say that

u=f(1−1/m)=15(1−1/m)=−10

1−1/m=−2/3

i,e 1/m=5/3

m=3/5

So, hi=3/5×h0=3/5×5= 3 cm

similarly, v=f(1−m)=15(1−3/5)=+6cm

So, virtual image is formed.

Image distance=6 cm behind the mirror

Size= 3 cm