PCB Design — question 1 of 10
Write a real answer. It is graded against the question's rubric, and the mastery movement is computed by the same engine the product uses. Scoring here is deterministic rather than model-written, so this page costs nothing to run and nothing is saved. In a track built from your own posting, the same rubric is graded by the model, which is what produces feedback about your reasoning rather than about coverage.
IPC-2221 gives an empirical relation for external layers: I = k * (ΔT)^0.44 * A^0.725, where k≈0.048, ΔT is temperature rise in °C, and A is cross-sectional area in mil².
A trace on an outer copper layer is 20 mils wide, 1oz copper, and you're allowed a 20°C temperature rise above ambient. Using the IPC-2221 style external-layer current-capacity relationship, estimate roughly how much continuous current that trace can carry. Walk me through your reasoning, not just a number pulled from a chart.
This one resolves to a number. Give the value in the field below and your reasoning in the box — the number is checked exactly, by arithmetic.