Basic Qualification · B-005 Basic electronics and theory · B-005-006-007
Which of these combinations of resistors could make up a 50-ohm dummy load capable of safely dissipating 5 watts?
- ATen quarter-watt 500-ohm resistors in parallel
- BFour 2-watt 200-ohm resistors in parallel
- CTwo 5-watt 100-ohm resistors in series
- DTwo 2-watt 25-ohm resistors in series
Correct answer: B — Four 2-watt 200-ohm resistors in parallel. From the official ISED question bank, verified word for word.
Why
Four 2-watt 200-ohm resistors in parallel work because connecting four identical resistors this way divides the total resistance by four, giving exactly 50 ohms, while the power rating adds up to eight watts, which safely exceeds the required five watts. The full explanation — and one for every question — is in Pro.
Practise this section
Basic electronics and theory is section B-005 of the Basic exam: The theory: Ohm's law, power, series and parallel circuits, AC and DC, frequency and wavelength, decibels, and the metric prefixes the exam leans on.
Drill B-005 — free, no account