Question

in common emitter amplifier current gain is 80 and emitter current is 9 ma the base current is​

Answer 1

Given :  Emitter amplifier current gain (β) = 80

            emitter current = 9ma

To find : base current

Solution :

For transistor, β= collector current / base current

Also, emitter current = collector current + base current

        collector current = emitter current - base current

Therefore, β = (emitter current-base current) / base current

                 80= emitter current / base current -1

                 80 = 9/base current - 1

                 81 = 9/base current

                 9/81 = base current

                  1/9ma = base current

Therefore, base current is 1/9 ma