Two point sources S₁ and S₂ are 24 ~cm apart. Where should a convex lens of focal length 9 ~cm be placed in between them, so that the images of both sources are formed at the same place?

Step-by-step solution

The given condition will be satisfied only if one source (S₁ ) placed on one side such that u f (i.e. it lies beyond the focus). If S₁ is the object for the lens, then If S₂ is the object for the lens, then Adding (i) &(i i) , we get aligned & 1 x + 1 (24-x) = 2 f = 2 7 & x^2-24 x+108=0 x=18 ~cm and x=6 ~cm aligned So, the correct answer will be 6 ~cm .