Transcript PRACTICAL # 03

To Measure Resistance using Color Band
By: Engr.Irshad Rahim Memon
 Calculate
the resistance value by 4-band
color coding (Fixed resistor)
 Calculate the resistance value by 5-band
color coding (Fixed resistor)
 Measure the resistance by using “Multi
meter”
A
component that is specifically designed to have a
certain amount of resistance is called a resistor.
The principal applications of resistors are to limit
current in a circuit, to divide voltage, and, in
certain cases, to generate heat.
 Although resistors come in many shapes and sizes,
they can all be placed in one of two main
categories: fixed and variable.
 The electronic color code is used to indicate the
values or ratings of electronic components, very
commonly for resistors, but also for capacitors,
inductors, and others.
 Color-coding
of this form is becoming rarer.
In newer equipment, most passive
components come in surface mount packages
 Many of these packages are unlabeled, and
those that are labeled normally use
alphanumeric codes, not colors.
 In one popular marking method, the
manufacturer prints 3 digits on components:
2 value digits followed by the power of ten
multiplier
 Thus
the value of a resistor marked 472 is
4,700 Ω, a capacitor marked 104 is 100 nF
(10x104 pF), and an inductor marked 475 is
4.7 H (4,700,000 µH)
 This can be confusing; a resistor marked 270
might seem to be a 270 Ω unit, when the
value is actually 27 Ω (27×100).
 4-bands
Color coding Table:
 The
first band is the first digit of the
resistance value.
 The second band is the second digit of the
resistance value.
 The third band is the number of zeros
following the second digit, or the multiplier.
 The fourth band indicates the percent
tolerance and is usually gold or silver.
 First
band-1st digit
 Second band-2nd digit
 Third band-3rd digit
 Fourth band-multiplier
 Fifth band-tolerance
 Color
Band of 4-band,5-band and 6-band
resistors have been verified and observed