The solid angle subtended by the periphery of an area 1 cm2 at a point situated symmetrically at a distance of 5 cm from the area is

Question

The solid angle subtended by the periphery of an area 1 cm2 at a point situated symmetrically at a distance of 5 cm from the area is (A) 2 × 10-2 steradian (B) 4 × 10-2 steradian (C) 6 × 10-2 steradian (D) 8 × 10-2 steradian

Tardigrade Admin · Accepted Answer

Solid angle, d Ω=(d A/r2)=(1 cm2/(5 cm)2) =4 × 10-2 steradian

Q. The solid angle subtended by the periphery of an area $1 c m^{2}$ at a point situated symmetrically at a distance of $5 c m$ from the area is

$2 \times 1 0^{- 2}$ steradian

$4 \times 1 0^{- 2}$ steradian

$6 \times 1 0^{- 2}$ steradian

$8 \times 1 0^{- 2}$ steradian

Solid angle, $d Ω = \frac{d A}{r ^{2}} = \frac{1 c m ^{2}}{( 5 c m ) ^{2}}$
$= 4 \times 1 0^{- 2}$ steradian

Q. The solid angle subtended by the periphery of an area 1cm2 at a point situated symmetrically at a distance of 5cm from the area is

2×10−2 steradian

4×10−2 steradian

6×10−2 steradian

8×10−2 steradian