# Geometrical optics, refraction

## Homework Statement

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.

The equation which you used
Is correct
Just set the boundary conditions
And use proper sign convention
(If the light ray is incident from the denser medium to the rarer, the image distance and radius are positive and the object distance is negative)
Remember that the image formed is a real one and thus will converge at one point or the other in the denser or the rarer medium
The distance of the image will be measured from the boundary obviously
The formula
Is used is
That for
Refraction at A Spherical Interface

UchihaClan13

Object dist. Tending to infinite? And img dist. 'f'? That didn't gave me the answer. Please post the exact solution.

Is the object placed in the first medium??
(The rarer one?)
I can give you small hints
But I cannot give you the entire answer

Is the object placed in the first medium??
(The rarer one?)
I can give you small hints
But I cannot give you the entire answer
I got it. I placed object in the wrong medium. My bad

Is the object placed in the first medium??
(The rarer one?)
I can give you small hints
But I cannot give you the entire answer
I got it. I placed object in the wrong medium. My bad