Question

Plz and this question I will mark them as BRAIN​

Answer 1

Answer:

(a)

(i)Angle of incidence = 90-30 = 60°

(ii)Angle of refraction = 90-45 = 45°

(b) u(liq relative to air ) = √(3/2)

Explanation:

(b) using Snell's law ,

u(air) x sin(60°) = u(liq) x sin(45°)

=> u(liq)/u(air) = sin(60°)/sin(45°)

=> u(liq)/u(air) = √3/2 x √2

=> u(liq relative to air) = √6/2 or √3/√2 or √(3/2) ...

Answer 2

a) i) 60°

This is because , angle of incidence means the angle the incident ray forms with the normal. Here the angle formed by the incident ray with the medium surface is 30° so, the angle with normal will be 90°-30° = 60°

ii) 45°

Again, angle of refraction is the angle formed by the refracted ray with the normal. In the figure the angle formed by the refracted ray is with the surface of medium. And so, the angle of refraction will be 90°-45° = 45°

b) Snell's law is = sin i/ sin r

we know here,

i {angle of incidence} = 60°

r { angle of refraction} = 45°

So,

$\frac{ \sin(i) }{ \sin(r) } = \frac{ \sin(60) }{ \sin(45) }$

=>$\frac{ \frac{ \sqrt{3} }{2} }{ \frac{1}{ \sqrt{2} } }$

=>$\sqrt{ \frac{3}{2} }$

And thus the answer is √3/√2 or 1.22

Cheers!