eng Ansari Education and Research Society Journal of Ultra Scientist of Physical Sciences December 2010 22 3 567 572 juc 930 article S. Singh 1 T. S. Chauhan 2 Department of Physics, Bareilly College, Bareilly- 243005 UP (INDIA) Department of Mathematics, Bareilly College, Bareilly - 243005 (UP) INDIA <p style="text-align: justify;">This paper reports to the investigations on the study of an unsteady two-dimensional laminar boundary layer flow of an incompressible, viscous, electrically conducting fluid past an infinite porous flat plate. The flow was subjected to a uniform transverse magnetic field. The plate was assumed to move with a constant velocity along the direction of fluid flow. The free stream velocity was subjected to an exponentially decreasing small perturbation law. Injection (or blowing) at the plate has also been assumed to vary exponentially with time. We have derived analytical expressions for velocity field in the boundary layer and skin friction at the plate .Variation of velocity in the boundary layer and skin friction at the plate with different amounts of blowing have been shown in various graphs. The investigation shows that the skin friction at the plate can be reduced either by increasing the blowing or by decreasing the applied magnetic field or both. At a given location in the boundary layer, velocity increases with decrease in the amount of injection or with increase in applied magnetic field.</p> <p style="text-align: justify;">&nbsp;</p> https://ultraphysicalsciences.org/paper/930/ MHD Injection Boundary layer flow Skin-friction free stream velocity