A point charge of +12μC is at a distance 6 cm vertically above the centre of a squared of side 12 cm as shown in figure. The magnitude of the electric flux through the square will be........... ×103Nm2/C.
Answer: 226
Solution
The charge is 6 cm above the centre of a square of side 12 cm, which places it exactly at the centre of a cube of edge 12 cm having that square as one face. By symmetry the total flux ε0q divides equally among the six faces, so
Φ=61⋅ε0q=6×8.85×10−1212×10−6=2.26×105Nm2C−1
The magnitude of the flux through the square is 226×103Nm2/C.
JEE Main · 2021 · 24 Feb 2021 · Shift 2 · Integer answer