Examkin

Question

Difficulty: MediumResistors and Potentiometers

An electronics technician is replacing a scorched four-band resistor on a circuit board. The original component has the color sequence Blue, Gray, Brown, and Gold. What is the nominal resistance and tolerance of this resistor?

  1. A
    6.8 kΩ±5%6.8\text{ k}\Omega \pm 5\%
  2. B
    68 Ω±5%68\ \Omega \pm 5\%
  3. 680 Ω±5%680\ \Omega \pm 5\%Answer
  4. D
    570 Ω±5%570\ \Omega \pm 5\%

Answer

680 Ω±5%680\ \Omega \pm 5\%
According to standard electronic color code conventions, blue represents the digit 6, gray represents 8, brown denotes a multiplier of 10 (or 10110^1), and gold denotes a ±5%\pm 5\% tolerance. Combining these yields 68×10=680 Ω±5%68 \times 10 = 680\ \Omega \pm 5\%.

Step-by-Step Solution

1
Determine the first two significant digits from the first and second color bands.
The first band (Blue) is 66 and the second band (Gray) is 88, forming the number 6868.
In a standard four-band resistor code, the first two bands represent significant digits.
2
Apply the decimal multiplier from the third color band.
The third band (Brown) represents a multiplier of 101=1010^1 = 10, yielding 68×10=680 Ω68 \times 10 = 680\ \Omega.
The third band specifies the power of ten by which the significant digits are multiplied.
3
Identify the tolerance percentage from the fourth color band.
The fourth band (Gold) designates a tolerance of ±5%\pm 5\%.
Gold in the fourth position standardly denotes a ±5%\pm 5\% manufacturer tolerance rating.

Key Concept

Four-band resistor color code decoding and tolerance interpretation
Estimated Time:35s
Rate this question

Topics

Resistors and Potentiometers

More questions from this topic