An $npn$ bipolar junction transistor (BJT) is operating in the active region. If the reverse bias across the base-collector junction is increased, then
- the effective base width increases and common-emitter current gain increases
- the effective base width increases and common-emitter current gain decreases
- the effective base width decreases and common-emitter current gain increases
- the effective base width decreases and common-emitter current gain decreases