Electric Charges and Fields - Result Question 43
43. A charge $Q$ is placed at the corner of a cube. The electric flux through all the six faces of the cube is
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(a) $Q / 3 \varepsilon_0$
(b) $Q / 6 \varepsilon_0$
(c) $Q / 8 \varepsilon_0$
(d) $Q / \varepsilon_0$
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Answer:
Correct Answer: 43. (c)
Solution:
(c) According to Gauss’s theorem, electric flux through a closed surface $=\frac{Q}{\varepsilon_0}$ where $q$ is charge enclosed by the surface.
The charge is kept at a corner of a cube so it can be visualised as being at the centre of 8 cubes.
$\therefore \quad$ The flux through each cube will be $\frac{1}{8}$ of the flux $\frac{\theta}{E_o}$
$\therefore \quad$ Flux through all six faces $=\frac{\theta}{8 E_O}$
