EET-112: Elementary Electronics
UNIT1 SUPLEMENTARY MATERIALS - Pictures of commonly used components
Resistor size varies
with power (P), which
indicates how much
current (I) it can allow
at a given voltage (V).
P = VI
RESISTORS
Color band on the
resistor will indicate
the value of the
resistor. As detailed
below.
CAPACITORS
DIODES
Unit 1sup/page 1 of 4
EET-112: Elementary Electronics
TRANSISTORS
Unit 1sup/page 2 of 4
EET-112: Elementary Electronics
CIRCUIT BOARD - SURFACE MOUNT
Unit 1sup/page 3 of 4
EET-112: Elementary Electronics
Reading Resistance Values:
Resistance is measured in ohms, the symbol for ohm is an omega . 1 is quite small so resistor
values are often given in k and M . 1 k = 1000
1 M = 1000000 .
Resistor values are normally shown using colored bands. Each color represents a number as shown in
the table.
The Resistor Color Code
Colour Number Multiplier
Tolerance
Black
0
1
-
Brown
1
10
±1%
Red
2
100
±2%
Orange
3
1000
±3%
Yellow
4
10,000
±4%
Green
5
100,000
-
Blue
6
1,000,000
-
Violet
7
10,000,000
-
Grey
8
100,000,000
-
White
9
Gold
-
0.1
±5%
Silver
-
0.01
±10%
None
-
-
±20%
Most resistors have 4 bands:
• The first band gives the first digit.
• The second band gives the second
digit.
• The third band indicates the number of
zeros.
• The fourth band is used to shows the
tolerance (precision) of the resistor
-
red (2), violet (7), yellow (4 zeros) and gold bands.
So its value is 270000 = 270 k .
Small Value Resistances
red, violet, gold bands represent 27 × 0.1 = 2.7
blue, green, silver bands represent 56 × 0.01 = 0.56
Unit 1sup/page 4 of 4