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Electric Charges and Fields — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectric Charges and Fields1 Mark
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

  1. $4\pi$

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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