 This applied voltage causes the lower P-N junction to become forward biased, allowing a flow of electrons from the emitter into the base.In active mode, the electric field existing between base and collector (caused by "V"CE) will cause the majority of these electrons to cross the upper P-N junction into the collector to form the collector current "I"C. The remainder of the electrons recombine with holes, the majority carriers in the base, making a current through the base connection to form the base current, "I"B.As shown in the diagram, the emitter current, "I"E, is the total transistor current, which is the sum of the other terminal currents, (i.e., "I"E = "I"B + "I"C).