MCQ
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:
- A2 × 10-2 steradian.
- B4 × 10-2 steradian.
- C6 × 10-2 steradian.
- D8 × 10-2 steradian.
✓
Answer
- 4 × 10-2 steradian.
Explanation:
Solid angle, $\text{d}\Omega=\frac{\text{dA}}{\text{r}^2}=1\text{cm}^2/(\text{ 5cm})^2$
$=0.04$ steradian
$=4\times10^{-2}$ steradian
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