<prompt> RMP of a smooth muscle cell is:- 10 mV to - 20 mV- 45 mV to - 55 mV- 65 mV to - 75 mV- 85 mV to - 90 mV  <response>: The membrane potential of a smooth muscle fiber has no true resting value. However, in periods of relative quiescence it is about - 45 to - 55 mV. The reason for this low RMP of smooth muscle, compared to skeletal muscle, is the relatively high intracellular and relatively low in the smooth muscle. 