colour resistor

Scientific and Engineering Notations

Standard Form or Scientific Notation

A number written with one digit to the left of the decimal point and multiplied by 10 raised to some power is written in standard form or with scientific notation, ex.

43712 = 4.3712 · 10⁴  

0.036 = 3.6 · 10^-2 

Engineering Notation

Engineering notation is similar to scientific notation except that the power of ten is always a multiple of 3, ex.

43712 = 43.712 · 10³ = 0.043712 · 10⁶  

0.036 = 36 · 10^-3 = 36000 · 10^-6

Units used in engineering may be made smaller or larger with the use of prefixes, ex.

4.7 kJ = 4.7 · 10³ J = 4700 J

8 MV = 8 · 10⁶ V = 8000000 V

What is Ohm's Law?

The relationship between Resistance, Voltage and Power

Ohm's law is a simple equation that shows the relationship between resistance, voltage and current through a metal wire, or some other type of resistive material. In mathematical terms, Ohm's law is written as:
I = V/R ,
where I is the current (Amps), V is the voltage (Volts), and R is the resistance (Ohms).



Ohm's law can also show the relationship between resistance, voltage and power using the following equation:
P = V 2/R ,
where P is the power (Watts), V is the voltage (Volts), and R is the resistance (Ohms).

What is a Resistor

What is a Resistor?
Resistor is electrical or electronic components which resist the flow of current across the resistor device.

Resistor Symbol

The resistance to current flow results in a voltage drop across the resistor device. Resistors are used extensively throughout electrical and electronic circuits.

Resistor devices may provide a fixed, variable, or adjustable value of resistance. Adjustable resistors are refers to as rheostats, or potentiometers. Resistor values are expressed in Ohms, the electric resistance unit.

Resistors are incorporated within a electrical or electronic circuit create a known voltage drop or current to voltage relationship.

If the electrical current in a circuit is known (current is measured in amperes), then a resistor can be used to create a known potential difference (voltage difference) proportional to that current.

Conversely, if the voltage drop (potential difference) across two points in a circuit is known, a resistor can be used to create a known current proportional to that difference.

An attenuator is a network of two or more resistors (a voltage divider).

A line terminator is a resistor at the end of a transmission line or daisy chain bus, designed to match impedance and minimize reflections of the electronic signal.