🔍 Key Concepts

• NPN transistor biasing – how the base-emitter junction must be biased for conduction • Typical silicon diode forward voltage values • Difference between silicon and germanium junction voltages

💭 Think About

• Think about the base-emitter junction of an NPN transistor as if it were a diode. In which direction must it be biased for current to flow? • What is the typical forward voltage drop across a silicon junction when it begins to conduct significantly? • Which answer choices match both the correct polarity and a realistic voltage for a silicon base-emitter junction?

✅ Before You Answer

• Confirm the correct polarity of the base relative to the emitter in an NPN transistor for normal operation • Verify the typical forward voltage of a silicon junction (not germanium) when it is conducting • Eliminate any options that have the wrong sign (positive vs. negative) or an unrealistic threshold voltage for silicon