A fish looking from within water sees the outside world through a circular horizon. If the fish is √7 m below the surface of water, what will be the radius of the circular horizon ?

Question

A fish looking from within water sees the outside world through a circular horizon. If the fish is √7 m below the surface of water, what will be the radius of the circular horizon ? (A) 3 m (B) (3/√7) m (C) √7 m (D) 3 √7 m

Tardigrade Admin · Accepted Answer

Refractive index of water, μ=4 / 3 <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/b4a0837f3cbf63c9bb2d8cf0d7b14de6-.png" /> sin C=(1/μ)=(3/4) tan C=(3/√7) dots(i) From figure tan C=(A D/O D)=(r/√7) dots(ii) From equations (i) and (ii), we get r =3 m

Q. A fish looking from within water sees the outside world through a circular horizon. If the fish is $7 m$ below the surface of water, what will be the radius of the circular horizon ?

$3 m$

$\frac{3}{7} m$

$7 m$

$37 m$

Refractive index of water, $μ = 4/3$

$sin C = \frac{1}{μ} = \frac{3}{4}$
$tan C = \frac{3}{7} \dots (i)$
From figure
$tan C = \frac{A D}{O D} = \frac{r}{7} \dots (ii)$
From equations (i) and (ii), we get
$r = 3 m$

Q. A fish looking from within water sees the outside world through a circular horizon. If the fish is 7​m below the surface of water, what will be the radius of the circular horizon ?

3m

7​3​m

7​m

37​m