Which statement is true about the first two bands on a resistor?

Which statement is true about the first two bands on a resistor?

• A. They determine the multiplier
• B. They determine the first two significant digits
• C. They determine the tolerance
• D. They determine the last digit

Answer: (B)

On a resistor with the standard color code, the first two bands are the first two significant digits of the resistance value. Each color maps to a digit: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, white 9. The value you read is formed by those two digits, then multiplied by 10 to the power given by the third band. The last band tells you the tolerance. So, for example, if the first two bands are brown and black, you have digits 1 and 0, giving 10. If the multiplier (the third band) is red (×100), the resistor’s value becomes 10 × 100 = 1000 ohms. The tolerance is indicated by the fourth band, such as gold for ±5% or silver for ±10%. This is why the correct statement is that the first two bands determine the first two significant digits.

On a resistor with the standard color code, the first two bands are the first two significant digits of the resistance value. Each color maps to a digit: black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, gray 8, white 9. The value you read is formed by those two digits, then multiplied by 10 to the power given by the third band. The last band tells you the tolerance.

So, for example, if the first two bands are brown and black, you have digits 1 and 0, giving 10. If the multiplier (the third band) is red (×100), the resistor’s value becomes 10 × 100 = 1000 ohms. The tolerance is indicated by the fourth band, such as gold for ±5% or silver for ±10%.

This is why the correct statement is that the first two bands determine the first two significant digits.