On a color-coded resistor, which two bands are used to form the first two significant digits of the resistance value?

On a color-coded resistor, which two bands are used to form the first two significant digits of the resistance value?

• A. Second and Third
• B. First and Second
• C. First and Third
• D. Third and Fourth

Answer: (B)

The first two bands on a four-band resistor encode the first two significant digits of the resistance. The third band is the multiplier (how many zeros to add), and the fourth band gives the tolerance. So the two bands that form the first two digits are the first and second bands. For example, if the first band is brown (1) and the second is black (0), you have 10 as the digits; with a multiplier band of red (×100), the value becomes 10 × 100 = 1000 ohms (1 kΩ).

The first two bands on a four-band resistor encode the first two significant digits of the resistance. The third band is the multiplier (how many zeros to add), and the fourth band gives the tolerance. So the two bands that form the first two digits are the first and second bands. For example, if the first band is brown (1) and the second is black (0), you have 10 as the digits; with a multiplier band of red (×100), the value becomes 10 × 100 = 1000 ohms (1 kΩ).