A resistor is a passive electrical component that implements electrical resistance. It is used to reduce current flow in electronic circuits. Resistance is measured in units called ohms, after Georg Ohm. The resistance of resistors can be measured using a resistor color code system. This involves identifying the colors on the resistor bands to determine the nominal value and tolerance range in ohms.

1. Mr. Ian Keith R. Somoza

2. Let’s have a
quick
ACTIVITY!

5. Have you
seen a
resistor?

8. • A resistor is a passive two-
terminal electrical component that
implements electrical resistance as
a circuit element.
• In electronic circuits, resistors are
used to reduce current flow.

10. Resistance
The amount of opposition to the flow of
electrical current.
Measured in units called ohms, named
after German scientist and
mathematician Georg Simon Ohm.

11. How the Resistance of
the Resistors
Measured?

12. ?

13. Resistor Color Code

14. • 4-Band Resistors
• Convert nominal value to ohms (Ω)
• 1st
digit (from left to right) of nominal
value = 1st
color band
• 2nd
digit of nominal value = 2nd
band
• Number of zeros remaining = 3rd
(multiplier) band
• Tolerance = 4th
band

15. Tolerance Bands
To calculate tolerance range
• Determine the resistors stated
resistance from the color bands.
• Multiply the stated resistance times (x)
the tolerance percentage.
• Add and Subtract your tolerance figure
from the stated resistance to identify
the acceptable range.