🔍 Key Concepts

• Direction of conventional current vs electron current (they are opposite). • How the rectifier diodes (D1, D2) and transistor Q1 make the output across RL a unidirectional DC voltage with ground as the reference. • Role and polarity of CR1 and the grounded side of the circuit in setting which end of RL is more positive.

💭 Think About

• First, decide which end of RL (the TP5 end or the grounded end) is at the more positive potential during normal operation. • Then, think about the direction of conventional current through RL given that polarity, and finally reverse that direction to get the electron current direction. • Ask yourself: once the AC is rectified and filtered, can the polarity across RL ever reverse, or is it fixed by the diodes and transistor orientation?

✅ Before You Answer

• Verify which node (TP5 or ground) connects to the positive side of the rectified and filtered output. • Confirm the orientation of CR1’s arrow and Q1’s symbol to see which way conventional current is allowed to flow. • Before choosing, double‑check that you are answering for electron current, not conventional current, and reverse the direction if needed.