Which color bands indicate that a resistor is 100 ohms?

Which color bands indicate that a resistor is 100 ohms?

• A. Brown, Black, Brown, Gold
• B. Red, Violet, Yellow, Gold
• C. Brown, Gray, Red, Silver
• D. Blue, Black, Brown, Gold

Answer: (A)

Resistor color codes: the first two bands are the significant digits, the third is the multiplier (how many zeros to add), and the fourth is tolerance. Here, brown gives 1 and black gives 0, so the base digits are 10. The multiplier brown means 10^1, so 10 × 10 = 100. The final gold band indicates a tolerance of ±5%. So this color sequence encodes 100 ohms with 5% tolerance. Other options mix different digits or multipliers, which would yield values like 270k ohms, 1.8k ohms, or 600 ohms, not 100 ohms.

Resistor color codes: the first two bands are the significant digits, the third is the multiplier (how many zeros to add), and the fourth is tolerance. Here, brown gives 1 and black gives 0, so the base digits are 10. The multiplier brown means 10^1, so 10 × 10 = 100. The final gold band indicates a tolerance of ±5%. So this color sequence encodes 100 ohms with 5% tolerance. Other options mix different digits or multipliers, which would yield values like 270k ohms, 1.8k ohms, or 600 ohms, not 100 ohms.