Basic Qualification · B-004 Circuit components · B-004-006-001
On resistors with four colour bands, which colour band specifies the tolerance?
- A Fourth
- B Third
- C Second
- D First
Correct answer: A — Fourth. From the official ISED question bank, verified word for word.
Why
On a four-band resistor, the first two bands show the value, the third acts as a multiplier to scale that number, and the fourth band alone tells you the tolerance, which is the allowed margin of error in the resistance. The full explanation — and one for every question — is in Pro.
Practise this section
The parts inside the box: resistors, capacitors, inductors, diodes, transistors, tubes and what each does in a circuit.