A bar magnet of length $14 \,cm$ is placed in the magnetic meridian with its north pole pointing towards the geographic north pole. A neutral point is obtained at a distance of $18\, cm$ from the center of the magnet. If $B _{ H }=0.4 \,G ,$ the magnetic moment of the magnet is $\left(1\, G =10^{-4} T \right)$
$2.880 \times 10^{3}\, J \,T ^{-1}$
$2.880 \times 10^{2}\, J\, T ^{-1}$
$2.880\, J\, T ^{-1}$
$28.80\, J\, T ^{-1}$
Due to the earth's magnetic field, charged cosmic ray particles
The angle of dip at a certain place is $30^o$. If the horizontal component of the earth’s magnetic field is $H, $ the intensity of the total magnetic field is
If the dip circle is set at $45^o$ to the magnetic meridian, then the apparent dip is $30^o$. The true dip. of the place is
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 ............ $s$
Angle of dip is $90^o$ at