Carbon resistor colour code — compute the resistance value A carbon resistor has colour bands: yellow–violet–orange (first band = yellow, second band = violet, third band = multiplier). Determine the nominal resistance value in ohms (ignore tolerance band for this question).

Difficulty: Easy

Correct Answer: 47000 Ω

Explanation:


Introduction / Context:
This item checks your mastery of the resistor colour code used in electronics. Interpreting the digit bands and the multiplier band quickly and accurately is a core lab skill for circuit assembly and troubleshooting.



Given Data / Assumptions:

  • Band 1 (most significant digit): yellow.
  • Band 2 (second digit): violet.
  • Band 3 (multiplier): orange.
  • Tolerance band is not considered.


Concept / Approach:
The first two bands provide the significant figures; the third band gives the power-of-ten multiplier. Standard mapping: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9. Multipliers use the same exponents: orange means 10^3.



Step-by-Step Solution:
First digit (yellow) = 4.Second digit (violet) = 7.Multiplier (orange) = 10^3.Resistance = 47 * 10^3 Ω = 47000 Ω = 47 kΩ.



Verification / Alternative check:
Many resistor charts list yellow–violet–orange explicitly as 47 kΩ. A quick digital multimeter measurement on a typical E12/E24 resistor marked with these bands will read close to 47 kΩ within tolerance.



Why Other Options Are Wrong:
17000 Ω, 27000 Ω, and 37000 Ω use incorrect digit or multiplier interpretations. 56000 Ω corresponds to green–blue–orange, not yellow–violet–orange.



Common Pitfalls:
Reading the bands from the wrong end; confusing violet (7) with blue (6); misapplying the multiplier colour.



Final Answer:
47000 Ω

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