End
A of the rod acts as an object for mirror and A' will be its image. By mirror
formula, image distance of A is V_{A}.

V_{A}
= -15cm

Also
image distance of C

Vc= -20 cm

**∴**** **The length of image = | V_{A}-V_{C
}|

= | -15-(20) | = 5cm

Since the nature of image produced by a convex mirror is always virtual, erect and diminished.

*n*= 2;

*i*=90◦

*n *= sin *i* / sin *r*

sin
*r *= sin *i / n*

*= sin *90◦/2 = ½

r
= sin^{-1}(1/2) = 30◦

n =

No Explaination.

Since the liquid act as a plane sheet of glass its refractive index is equal to that of glass.

For
a plano-convex lens with its plane surface silvered

1/*f *= 2(*n *− 1)/*R*

*f
= R */ 2(*n *−
1) = 10 / 2(1.5* *− 1) = 10 / 2(0.5) =
10 *cm*

n
- 1.5 ; d' = nd

In
one side bubble depth is 5 cm

∴ Original depth = 1.5 x 5 = 7.5 cm

On
the other side depth is 3 cm

∴ Original depth = 1.5 x 3 = 4.5
cm

∴ Thickness is 7.5 + 4.5 = 12 cm

For
total internal reflection

* i* > C;

sin
*i* > sin C;

sin
45◦ > 1/*n*

1/√2
> 1/n

n>√2

n>1.414

Here, n=1.5