If a charge Q is placed as shown in figure, find the flux through this cube.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( \displaystyle\frac{Q}{4\varepsilon_{0}} \)
The charge sits on an edge of the cube. Four identical cubes meet along an edge, and together they would completely surround the charge. By Gauss’s law the total flux out of this block of four cubes is \( Q/\varepsilon_0 \). The four cubes are related by symmetry (turning the arrangement through \( 90^\circ \) about the edge leaves it unchanged), so each takes an equal share.
\( \displaystyle \Phi_{\mathrm{cube}} = \frac{1}{4}\times\frac{Q}{\varepsilon_0} = \frac{Q}{4\varepsilon_{0}} \)
Note: The same question was also asked in CUET (UG) 2023 on 13-06-2023 (Slot 3).