Question

A charge of 12 pC is placed at a distance of 10 cm directly above the centre of a square of side 20 cm .
What is the magnitude of electric flux through the square?

Answer 1

according to Gauss theorem,

first of all, we have to draw symmetrical surface is known as gaussian surface.

it is given that , A charge of 12pC is placed at a distance of 10cm directly above the centre of a square of side length 20cm.

so, we can make a cube which is perfect symmetrical surface.

you know, A cube has six faces and all of them are identical.

so, charge 12pC is shared in all faces.

then each face contains , q= 12pC/6 = 2pC charge.

now, electric flux through each face = $\frac{q}{\epsilon_0}$

= 2 × 10^-12C/(8.85 × 10^-12 C²/Nm²)

= 0.2259 Nm²/C

hence, answer is 0.2259 Nm²/C