Question

a concave mirror produces a real image of magnification 1/2, when an object is placed at a distance of 60cm from it. where the object should be placed, so that a virtual image of double the size is formed by the mirror?Experts

Answer 1

m= -v/u
-1/2 = -v/-60
Therefore, v= - 30.
Substitute values for v and u in mirror formula,
We get f=-20.
Let new object distance be u' and image distance be v'.
+2=-v'/u'
Therefore, v'=-2u'
Substitute values in mirror furmula,
1/-20 = (1/-2u') + (1/u')
This simplifies to
1/-20 = 1/2u'.
So, 2u'=-20
Therefore u'=-10 cm.