Match each of the items A, B and C with an appropriate item from 1, 2, 3, 4 and 5. In a bipolar junction transistor:
(A) the current gain increases
(B) the collector break-down voltage increases
(C) the cut-off frequency increases
1. the base doping is increased and the base width is reduced
2. the base doping is reduced and the base width is increased
3. the base doping and the base width are reduced
4. the emitter area is increased and the collector area is reduced
5. the base doping and the base width are increased