Question

In what way is Gauss’s law in magnetism different from that used in electrostatics? Explain briefly. 

The Earth’s magnetic field at the Equator is approximately 0.4 G. Estimate the Earth’s magnetic dipole moment. Given: Radius of the Earth = 6400 km.

Answer 1

As we know that Isolated positive or negative charge exists freely. So, Gauss’s law states that

∮\(\vec{E}\).d\(\vec{S}\)= \(\frac{1}{ɛ_0}\) |q|

Isolated magnetic poles do not exist. So, Gauss’s law states that

∮\(\vec{B}\).d\(\vec{S}\)= 0

Magnetic field intensity at the equator is