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A charge Q is placed at the centre of a cube. The electric flux emerging from any one face of the cube is

Asked in RS Academy GUJCET booklet · Flux through a cube

Answer: (4) Q/(6ε₀)

Step-by-step solution

Idea: Gauss's law gives the total flux out of the closed cube, φ=Q/(ε₀), since Q is inside.

With Q at the centre, all six faces are placed identically around it, so by symmetry each carries the same flux.

φ_face=1/6×Q/(ε₀)=Q/(6ε₀)

Why the other options are wrong

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