A spherical surface of roc 10 cm separates 2 media x and y of refractive indices 3/2 and 4/3 respectively. Centre of the spherical surface lies in the denser medium. An object is placed i x medium. For image to be real, the object distance must be ----
A) >90 cm
B) <90 cm
C) >80 cm
D) <80 cm
Homework Equations- i don't know relevant questions[/B]
The Attempt at a Solution
I used the formula u2/v - u1/u = (u2 - u1)/R. Where u2= 3/2 and u1= 4/3. But i dont think that that is right.