How many significant digits are indicated by the 5-band resistor code compared to the 4-band code?

How many significant digits are indicated by the 5-band resistor code compared to the 4-band code?

• A. Three digits; two digits
• B. Two digits; three digits
• C. Three digits; three digits
• D. Four digits; two digits

Answer: (A)

In resistor color coding, the number of significant digits is determined by how many digit bands appear before the multiplier. The five-band system uses three significant digits, then a multiplier, then tolerance. The four-band system uses two significant digits, then a multiplier, then tolerance. So the five-band code conveys three digits, while the four-band code conveys two digits. For example, a five-band resistor with bands brown, black, red, orange, gold encodes 102 × 10^3 ohms (102 kΩ) with ±5% tolerance, whereas a four-band resistor with brown, black, orange, gold encodes 10 × 10^3 ohms (10 kΩ) with ±5% tolerance. The extra digit in the five-band system is what increases the count of significant digits.

In resistor color coding, the number of significant digits is determined by how many digit bands appear before the multiplier. The five-band system uses three significant digits, then a multiplier, then tolerance. The four-band system uses two significant digits, then a multiplier, then tolerance. So the five-band code conveys three digits, while the four-band code conveys two digits. For example, a five-band resistor with bands brown, black, red, orange, gold encodes 102 × 10^3 ohms (102 kΩ) with ±5% tolerance, whereas a four-band resistor with brown, black, orange, gold encodes 10 × 10^3 ohms (10 kΩ) with ±5% tolerance. The extra digit in the five-band system is what increases the count of significant digits.