Resistors
E-SERIES
E24 series
24 values: ±5% tolerance
E12 series
12 values: ±10% tolerance
E6 series
six values: ±20% tolerance
E3 series
three values: 1, 2.2 and 4.7
Standard resistors values
Resistance
Types of resistance
DC Resistance
no frequency in DC circuits
magnitude of DC is constant
AC Resistance
overall resistance in AC circuits
Resistance = Impedance
R = Z
Resistance Formula 2
Power and Voltage
P=V*I
product of supply voltage and electric current.
Resistance Formula 1
Ohm’s Law
V = I * R
ratio of supply voltage and current.
resistance of conducting material
It depends on the temperature
depends on the nature of the material
inversely proportional to the cross-sectional area of the material
directly proportional to the length of the material
Unit
volt per ampere.
electrical component
measure of the opposition to current flow
Main topic
Colour code
specify the resistance value
tolerance
used to identify the values of resistors
Resistors in Parallel
1/Rtotal= 1/R1+1/R2+1\R3+.........+1/RN
resistors in series
Rtotal = R1 + R2 + R3 +……+Rn
unit of resistors
Ohm
two-terminal electrical component
device used in electrical circuits
step up or lower the voltage
Application
used in digital multi-meter
used for controlling temperature
used in modulators
Types
Magneto-resistors
Light Dependent Resistors
Varistors
Thermistors
Variable Resistors
Fixed Resistors