Question

The focal lengthof converging mirror is 20 cm .A object 4 cm in size , is placed at 60 cm infront of mirror . Find the nature and size of the image.

Answer 1

f=-20cm
ho=4cm
hi=?
u=-60cm
by using mirror formula
1/f=1/v+1/u
1/-20=1/v+1/-60
1/-20=1/v-1/60
1/-20+1/60=1/v
-3+4/60=1/v
-30=v
by ising manification formula
m=-v/u
m=30/-60
m=1/-2
then
m=hi/ho
1/-2=hi/4
4/-2=hi
-2=hi means height of the image.
nature is real, inverted and smaller than the object size.

Answer 2

Concave mirror
f=-20 cm
u=-60cm
using mirror  formula
1/f=1/v+1/u
   1/f-1/u=1/v
1/-20 +1/60=1/v

v=   -30 cm

hi= -v/u×ho
     +30/-60×4

=-2cm
       image is diminished and real,inverted.....