COMEDK Exam 2012 Solved Paper

Here, R=−0.1cm,µg=1.5
∴u=−0.1cm
From refraction formula,

µa−µg

R

=

µa

v

−

µg

u

⇒

1−1.5

−0.1

=

1

v

−

1.5

(−0.1)

(∵µa=1)
⇒5=

1

v

+1.5
⇒v=−

1

10

=−0.1cm
Here, negative sign shows that the image will be seen on the same size as that of object.
∴ The spot appears to be 0.1cm below the top surface or exactly at the original position.