  Pulsar braking torques due to magnetodipole radiation and to unipolar
generator are considered, which results in braking index being less than 3 and
could be employed to test the emission models. Improved equations to obtain
pulsar braking index and magnetic field are presented if we deem that the
rotation energy loss rate equals to the sum of the dipole radiation energy loss
rate and that of relativistic particles powered by unipolar generator. The
magnetic field calculated by conventional way could be good enough but only
modified by a factor of ~0.6 at most. Both inner and outer gaps may coexist in
the magnetosphere of the Vela pulsar.
