If image is real, it will be inverted which means height of image will be taken as negative. Also, the height of object is always positive.
Now as magnification = Height of image / Height
Therefore, in case of real image,
Magnification = Height of image (-) / height of object (+)=Negative.
So, Magnification will be negative.
Similarly, if image is virtual, it will be erect.
Therefore, in case of virtual image,
Magnification = Height of image (+) / height of object (+)= Positive
So, Magnification will be positive. of object.
-Answered by Nishant Verma On 17 October 2019:02:32:30 PM