Q 1.18)

A point charge +10 μC is at a distance 5 cm directly above the centre of a square of side 10 cm, as shown in Fig. What is the magnitude of the electric flux through the square?

( Hint: Think of the square as one face of a cube with edge 10 cm)

Question 1.18                        


It can be considered that the charge is placed at the centre of a cube of edge 10 cm.
According to Gauss's theorem, the total electric flux is through all its six faces:

ϕTotal=qε0
Hence, the electric flux through one face of the cube:
ϕ=ϕTotal6=16qε0

As

q=10 μC=10×106 C
ϕ=1610×1068.854×1012
=1.88×105 Nm2C1