Context: In a grounded-emitter transistor circuit, such as the light-switch circuit shown, as the base voltage rises, the emitter and collector currents rise exponentially. The collector voltage drops because of reduced resistance from collector to emitter. If the voltage difference between the collector and emitter were zero (or near zero), the collector current would be limited only by the load resistance (light bulb) and the supply voltage. This is called saturation because current is flowing from collector to emitter freely. When saturated, the switch is said to be on.

Question: Why does the collector voltage drop in grounded-emitter transistor circuits?
Answer: reduced resistance from collector to emitter

Question: What would happen if the voltage difference from collector and emitter were zero?
Answer: the collector current would be limited only by the load resistance (light bulb) and the supply voltage

Question: What is the term for a zero difference between collector and emitter?
Answer: saturation

Question: Why is the term saturation named as such?
Answer: current is flowing from collector to emitter freely

Question: What position is the switch in when saturated?
Answer: on

Question: What causes reduced resistance from collector to emitter?
Answer: Unanswerable

Question: Why does "current" have that name?
Answer: Unanswerable

Question: What changes the most in a grounded-emitter transistor circuit?
Answer: Unanswerable

Question: What is the load resistance in a light bulb?
Answer: Unanswerable

Question: What changes the amount of supply voltage?
Answer: Unanswerable