Engine 2014: Electricity

1. A to eliminate the need for a collector-emitter battery for establishing forward collector-emitter bias
2. B to eliminate the need for a collector-emitter battery for establishing reverse collector-emitter bias
3. C to eliminate the need for an emitter-base battery for establishing forward emitter-base bias
4. D to eliminate the need for an emitter-base battery for establishing reverse emitter-base bias

Tip: press A-D to answer