Unsteady hydromagnetic Couette flow of a viscous incompressible electrically conducting
fluid in a rotating system is studied when the fluid flow within the channel is induced
due to the impulsive movement of the one of the plates of the channel. The plates of the
channel are considered porous and the magnetic field is fixed relative to the moving plate.
Exact solution of the governing equations is obtained by Laplace transform technique. The
expression for the shear stress at the moving plate is also obtained. Asymptotic behaviour
of the solution is analyzed for small as well as large values of time t to highlight the
transient approach to the final steady state flow and the effects of rotation, magnetic
field and suction/injection. It is found that suction has retarding influence on the
primary as well as secondary flow where as injection and time have accelerating influence
on the primary and secondary flows.