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 VA.
VA
= -15cm
Also
image distance of C
Vc= -20 cm
∴ The length of image = | VA-VC
|
= | -15-(20) | = 5cm
n= 2;
i=90◦
n = sin i / sin r
sin
r = sin i / n
= sin 90◦/2 = ½
r
= sin-1(1/2) = 30◦
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