Question

Find the solid angle of a spherical surface of area $1.5\pi r^2$ at its center.

• A. $1.5\pi sr$
• B. $0.5\pi sr$
• C. $2\pi sr$
• D. $0.75\pi sr$

Answer 1

The correct option is A $1.5\pi sr$

Solid angle of a spherical surface is given by:
$\Omega =\frac{S}{r^2}$
where:
$S:\text{Surface Area of the Sphere}$
$r:\text{Radius of the Sphere}$

Putting value, we get
$\Omega =\frac{1.5\pi r^2}{r^2}sr$
$\Omega =1.5sr$