Question

where the object is placed in order to obtain a magnification of - 0.6 with a concave mirror

Answer 1

m= -v/u

m = -6 =-v/u
6u = u

1/6u+1/u=1/f
1+6/6u=1/f
7f/6 = u

Answer 2

Answer:

To obtain a magnification of -0.6 with a concave mirror, the object should be placed beyond the centre of curvature (that is 0.3).

Explanation:

• In a 'concave mirror', the magnification is the ratio of the "height of the object" or "image distance" to the "height of the object" or "object distance”.

         Magnification (M) = image distance (v) /object distance (u)  

• As per the Cartesian sign convention, the distance from the mirror to object is negative and from mirror to opposite side is positive.
• So when the object is placed "beyond the centre of curvature", the given magnification can be obtained.