1.

An object is kept in front of a concave mirror of focal length of 15cm image formed is 3 times the size of the object. Calculate the two possible distances of the object from the mirror.

Answer»

SOLUTION :Case (1) Image is real. M=-3
Here f=-15cm
Now m=-v/u=-3
Or, V=3u
From the mirror formula
1/f=1/u+1/v
-1/15=1/u+1/3u
Distance of the object U=-20cm
Case (2). When the image is virtual m=3
Now m=-v/u=3
or, V=-3
From the mirror formula
1/f=1/u+1/v
Then -1/15=1/u-1/3u
2/3u=-1/15
Distance of the object U=-10cm


Discussion

No Comment Found

Related InterviewSolutions