A thin metallic spherical shell of radius R carries a charge Q on its surface. A point charge Q/2 is placed at the centre C, and another charge + 2Q is placed outside the shell at A at a distance x from the centre as shown in the figure.
- Find the electric flux through the shell.
- State the law used.
- Find the force on the charges at the centre C of the shell and at the point A.
CBSE OUTSIDE DELHI - SET 2 EAST 2016
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- Electric flux through a Gaussian surface,
Net charge enclosed inside the shell q = 0
$\therefore$ Electric flux through the shell $\frac{\text{q}}{\in_{o}} = 0 $
even when the student writes - Electric flux through the shell is zero as electric field inside the shell is zero.
- Gauss Law - Electric flux through a Gaussian surface is $^1/∈_0$ times the net charge enclosed within it.
$\oint\overrightarrow{\text{E}}.\overrightarrow{\text{d}S} = \frac{\text{q}}{\text{E}_{o}}$
- Force on the charge at the centre i.e. Charges $^?/2 =0$
$ = \frac{1}{4\pi\text{E}_{o}}\frac{3\text{Q}^{2}}{\text{x}^{2}}$.
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