The earth's magnetic field lines resemble that of a dipole at the centre of the earth. If the magnetic moment of this dipole is close to $8 \times 10^{22}\, Am^2$, the value of earth 's magnetic field near the equator is close to....$Gauss$ (radius of the earth $= 6.4 \times 10^6\, m$)

The horizontal component of the earth's magnetic field at any place is $0.36 \times 10^{-4} Wb / m ^{2}$. If the angle of dip at that place is $60^{\circ}$, then the value of vertical component of the earth's magnetic field will be ........ $\times 10^{-4}\;W b / m^{2}$

The angle between the magnetic meridian and geographical meridian is called

The true value of angle of dip at a place is $60^o$, the apparent dip in a plane inclined at an angle of $30^o$ with magnetic meridian is

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 ............

At a place, the horizontal and vertical intensities of earth's magnetic field is $0.30$ Gauss and $0.173$  Gauss respectively. The angle of dip at this place is.....$^o$