p-channel JFET conduction direction: In a p-channel junction field-effect transistor (JFET), considering conventional current and electron flow, in which direction do electrons actually move through the device under normal operation?

Introduction / Context:
A p-channel JFET is a unipolar transistor whose majority carriers are holes. While circuit analysis usually uses conventional current (the flow of positive charge), understanding the actual electron flow clarifies device physics, terminal naming, and sign conventions in equations for gate–source voltage and drain current.

Given Data / Assumptions:

• Device is a p-channel JFET operated in its normal region (gate reverse-biased with respect to the channel).
• Majority carriers in the channel are holes.
• Conventional current direction is opposite to electron flow direction.

Concept / Approach:
In a p-channel JFET, conventional current flows from source to drain through a p-type channel when the gate is reverse-biased. Because electrons carry negative charge, their motion is opposite to conventional current. Therefore, if conventional current goes source → drain, electron flow must go drain → source. This is consistent with the electrostatic potentials used to bias a p-channel device (source more positive relative to drain in many textbooks’ sign conventions for p-channel JFETs).

Step-by-Step Solution:

Verification / Alternative check:
Think of a complementary n-channel JFET: conventional current goes drain → source, and electrons go source → drain. The p-channel case must invert both. Datasheet arrows and bias diagrams also reinforce these directions when comparing n- and p-channel devices.

Why Other Options Are Wrong:

• From source to drain: This is conventional current (holes) in p-channel, not electron flow.
• From source to gate / from drain to gate: With reverse-biased gate, only small leakage exists; the main conduction is channel, not to the gate.

Common Pitfalls:
Confusing conventional current with electron flow and mixing n-channel vs. p-channel direction conventions. Always invert directions when switching between charge types.

Final Answer:
from drain to source