A glass hemisphere of radius 0.04 m and refractive index of the material 1.6 is placed centrally over cross mark on a paper (i) with the flat face, (ii) with the curved face in contact with the paper. In each case, the cross mark is viewed directly from above. The position of the images will be

Options

A. (i) 0.04 m from the flat face, (ii) 0.025 m from the flat face
B. (i) at the same position of the cross mark, (ii) 0.025 m below the flat face
C. (i) 0.025 m from the flat face, (ii) 0.04 m from the flat face
D. for both (i) and (ii) 0.025 m from the highest point of the hemisphere

Answer

B

Explanation

`(mu_2)/(v)-(mu_1)/(u)=(mu_2-mu_1)/(R)`
`(1)/(v)-(1.6)/(-0.04)=(1-1.6)/(-0.04)`
`v=-0.04m`
Image of `O` is formed `O`.
`(1)/(v)-(1.6)/(-0.04)=0`
`v=-(0.04)/(1.6)=-0.025m`
`PI=0.025m`