Chapter 19 - Magnetism - Learning Path Questions and Exercises - Exercises - Page 691: 7

$2.0\times10^{-14}T$, left looking in the direction of the velocity.

To cancel the effect of gravity magnetic field should be in upward direction. So, magnetic field should be directed into the page or left looking in the direction of velocity. $F=qvB=mg$ Thus, $B=\frac{1.672\times10^{-27}\times10}{1.6\times10^{-19}\times5\times10^{6}}=2.0\times10^{-14}T$