In an NPN transistor, the collector current is 28 mA. If 80% electrons reach the collector, its base current in mA is

Step-by-step solution

Given I_C = 28 mA. Since 80 percent of the electrons emitted reach the collector, the collector current is given by: I_C = 80 100 I_E 28 = 0.8 I_E I_E = 28 0.8 = 35 mA The relation between emitter, base, and collector currents is: I_E = I_B + I_C I_B = I_E - I_C I_B = 35 - 28 = 7 mA Answer: 7 mA