MCQ
The solid angle subtended by the total surface area of a sphere at the centre is:
- A$4\pi$
- B$2\pi$
- C$\pi$
- D$3\pi$
✓
Answer
- $4\pi$
Explanation:
A steradian is the solid angle subtended at the center of a sphere of radius r by a section of its surface area of magnitude equal to r2. Since the surface area is $4\pi\text{r}^2$, there are $4\pi$ steradians surrounding a point in space.
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