Magnetism Questions

Ionized hydrogen atoms and $\alpha$ -particles with same momenta enter perpendicular to a constant magnetic field, $B$. The ratio of their radii of their paths $r_H:r_{\alpha }$ will be:

At a point $A$ on the earth’s surface the angle of dip, $\delta =+25^{\circ }$. At a point $B$ on the earth’s surface the angle of dip, $\delta =-25^{\circ }$. We can interpret that:

A cylindrical conductor of radius $R$ is carrying a constant current. The plot of the magnitude of the magnetic field $B$ with the distance $d$ from the centre of the conductor, is correctly represented by the figure:

The relation amongst the three elements of Earth's magnetic field, namely horizontal component $H$, vertical component $V$ and dip angle $\delta$ is ($B_E$ = total magnetic field):