Question

Resistance of a carbon resistor determined from colour codes is (22000±5%)Ω. The colour of third band must be:

• A. Yellow
• B. Red
• C. Green
• D. Orange

Answer 1

The Correct Option is D

To determine the colour of the third band on a carbon resistor from its resistance value, we need to understand how the colour coding system for resistors works. Each band on a resistor has a specific meaning:

• The first two bands represent the significant digits of the resistance value.
• The third band represents the multiplier (a power of 10).
• The fourth band represents the tolerance of the resistor.

The resistance given is \( (22000 \pm 5\%) \Omega \). We can break down the given resistance value:

• The digits "22" are the significant figures.
• The value "000" means the multiplicative factor is \(10^3\) since 22 followed by three zeroes equals 22000.

Using the resistor colour code:

• The significant digits (first two bands) of "22" correspond to the colours: Red (2) and Red (2).
• The multiplier of \(10^3\) corresponds to the colour Orange.
• The tolerance of \( \pm 5\% \) would typically be represented by the colour Gold, but this is not needed for determining the third band.

Thus, the third band must be Orange to denote a multiplier of \(10^3\).

Therefore, the correct answer is Orange.