An convex mirror used on a bus has a focal length of 200 cm. it a scooter is located at 100 cm. from this mirror find the position,nature and magnification of the image formed in the mirror.

As mirror is convex : f = 200 cm ; u = -100
Now : 1/f = 1/v +1/u 
=> 1/f - 1/u = 1/v
=> 1/200 - (-1/100) = 1/v
1 + 2/200 = 1/v
=> v = 200/3 = 66.66 cm 
As v is +ve therefore the image is virtual and is formed behind the mirror
Now: magnification = -(v/u) = -(-66.66/100) = .6666 
=> magnification is .66666