  We describe charged BHs, Penrose process for energy extraction from Kerr BHs
and Wald's proposal concerning a Kerr BH slowly becoming a Kerr-Newman BH in
the presence of a uniform magnetic field. In the context of BHs bearing
magnetic charge, we discuss both magnetic monopoles as well as dyons, and their
emergence from various models like string theory, GUTs and electroweak
theories, etc. In the later portions, we concentrate on our recent research
work pertaining to the non-relativistic dynamics of dyon-dyon interaction that
includes mutual gravitational attraction. From the derived classical equations
of motion, we obtain not only the well known Schwinger-Zwanziger quantization
condition for dyons using Saha's argument based on quantized angular momentum
of electromagnetic field but also a scalar virial theorem for an astrophysical
system consisting of point particles, some of which carry both electric and
magnetic charges. In the final sections, we obtain expressions for the
generated electromagnetic wave as well as gravitational wave amplitudes, and
the corresponding luminosities due to dyon-dyon interactions. Lastly, we
discuss the results after computing these quantities using a range of values
for the mass, electric and magnetic charges, etc. of the dyonic BHs.
