Question

an object of 5 cm height is placed at a distance of 10 cm from a convex mirror of radius of curvature with 30 cm. find the nature position and size of the image formed

Answer 1

h=5cm,
u=-10cm
f=15cm
1/f=1/v+1/u
1/15=1/v+1/-10
1/v=1/15+1/10=1/6
v=6cm
height of image =-6/-10*5=3cm
nature of image =virtual erect and enlarged

Answer 2

The focal length (f) of a convex mirror is positive and
                            Image distance (u)= -10 cm
                            Radius of curvature (R)=30 cm
                            so, f = 30/2=15 cm
 Substituting the value of u and f in MIRROR FORMULA, 
               i.e            1/v + 1/u = 1/f
                         you will get v=308/5=6 cm
Now, by using magnification fromula,
              i.e                m = -v/u
                          you will get m= -6/-10
                                   so m=0.6
and also  m=h'/h 
               so now by substituting the values of m(0.6) and h(5cm) in the formula 
                   you will get h'=6*5\10 = 3 cm
so NATURE    : VIRTUAL, ERECT
     POSITION :  BEHINd THE MIRROR 
     SIZE:             DIMINISHED