What was the recognition of Earth’s magnetic field ? State dynamo effect
Recognition of Earth's magnetic field was that a giant bar magnet placed along the axis of rotation of the Earth and deep in the interior. Magnetic field arising due to this reason. The magnetic field is now thought to arise due to electrical currents produced by convective motion of metallic fluids (consisting mostly of molten iron and nickel) in the outer core of the Earth, due to this reason magnetic arises. This is known as the dynamo effect.
The earth's magnetic field was flipped by $180^{\circ}$ a million years ago. This flip was relatively rapid and took $10^5 \,yrs$. Then, the average change in orientation per year during the flip was closest to ............ $s$
At the magnetic poles of the earth, a compass needle will be
At a certain location in Africa, a compass points $12^o$ West of the geographic North. The North tip of the magnetic needle of a dip circle placed in the plane of magnetic meridian points $60^o$ above the horizontal. The horizontal component of the earth's field is measured to be $0.16\, G$. The magnitude of the earth's field at the location will be
The values of the apparent angles of dip in two planes at right angles to each other are $45^{\circ}$ and $30^{\circ}$ respectively. The true value of angle of dip at the place is ............
If magnetic lines of force are drawn by keeping magnet vertical, then number of neutral points will be