WHAT IS RESISTOR?

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, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity.

Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. Resistors are also implemented within integrated circuits.

Two typical schematic diagram symbols are as follows:

(a) resistor, (b) rheostat (variable resistor), and (c) potentiometer


  IEC resistor symbol


Series and parallel resistors
The total resistance of resistors connected in series is the sum of their individual resistance values.


  R e q = R 1 + R 2 + ⋯ + R n .
The total resistance of resistors connected in parallel is the reciprocal of the sum of the reciprocals of the individual resistors.


  1/_{R e q} = 1 /_{R 1} + 1/ _{R 2} + ⋯ + 1/ _{R n} .
For example, a 10 ohm resistor connected in parallel with a 5 ohm resistor and a 15 ohm resistor produces 1/ _{(1/10 + 1/5 + 1/15)} ohms of resistance, or 30/₁₁ = 2.727 ohms.

A resistor network that is a combination of parallel and series connections can be broken up into smaller parts that are either one or the other. Some complex networks of resistors cannot be resolved in this manner, requiring more sophisticated circuit analysis.

What is the main function of resistor ?

Does a transformer has resistors?

Do resistors catch fire?

If a resistor is composed of carbon, does it degrade over time if in FREQUENT use?

If a resistor is composed of carbon, does it degrade over time if NOT in use?

If a resistor is composed of Metal, does it corrode over time if in FREQUENT use?

If a resistor is composed of Metal, does it corrode over time if NOT in use?

MarvhinMurillo wrote:Does a transformer has resistors?

As far as i know,  transformer doest have a resistor ( correct me if I'm wrong).  Resistors are replaced by transformers for reducing high voltage.  Ideal resistors dissipate power as heat to drop voltage.
Ideal transformers don't have power losses to transfer to a lower voltage.

garciarogelio wrote:What is the main function of resistor ?

The main function of resistors in a circuit is to control the flow of current to other components. For example,  take an LED. If too much current flows through an LED it is destroyed. So a resistor is used to limit the current.

Resistor is a tiny little conductor which conduct a electrical current through a circuit, it does not catches fire. Why? Because it has a small amount of electric current and does not comply a high voltage

How do we compute the value of ohms, of each resister if the load is complex?

It depends, why? If your resistor is carefully store in place where water doesn't any sign to suck, your resistor will remain in a good condition when uou have a good storage.

Peter Shaquelle Daling wrote:How do we compute the value of ohms, of each resister if the load is complex?

Complicated network of resistors can be computed by identifying the series and parallel resistors within the larger context of the circuit.

the resistor are passive components, meaning they only consume power (and can’t generate it). Resistors are usually added to circuits where they complement active components like op-amps, microcontrollers, and other integrated circuits. Commonly resistors are used to limit current, divide voltages, and pull-up I/O lines.

What is the main function of the resistor?

The main function of resistors in a circuit is to control the flow of current to other components. Take an LED (light) for example. If too much current flows through an LED it is destroyed. So a resistor is used to limit the current.

What is a simple circuit?

Simple circuits that have a single DC voltage source and a single resistor are the easiest to calculate. Although you could use Ohm's Law, you don't need it. The voltage drop across the resistor is the same as the voltage of the DC source. This comes from Kirchoff's Voltage Law, which states that all the voltages in a given circuit "loop" must add up to zero. For example, in a circuit with a 12V battery and 10K ohm resistor, the battery provides the 12V source and the resistor has a drop of 12V, adding up to zero.

when the resistor are invented????

who invented the resistor???

What is the resistors in parallel and series?

In series, circuits with resistors in series are a little more complicated than a single resistor, but here Ohm's Law comes to the rescue, though in a slightly different arrangement. First, add up the ohm values of all the resistors in the circuit. Here, we use a little algebra to get Ohm's Law for current: I=V÷R. Divide the DC source voltage by the total resistance to get the total current in the circuit. Since the circuit is a single loop, the current is the same through all resistors. To find the voltage drop for any one of the resistors, use Ohm's Law again, V=I*R, using the resistance of the resistor you want.

While in a parallel, a circuit that has only a DC voltage source and a set of resistors in parallel is easy again. The voltage drop across all the resistors is the same, and is equal to the DC source voltage. For example, put 3 resistors in parallel with a 12V battery. By Kirchoff's Voltage Law, each resistor is now its own loop. Each loop includes the battery, and the voltages add up to zero. Note that the current through each resistor is not the same, but in this case it doesn't matter.

When was the resistor invented?
Who was the inventor of a resistor?

Otis Boykin, who took a special interest in working with resistors, began researching and inventing on his own. He sought and received a patent for a wire precision resistor on June 16, 1959. This resistor would later be used in radios and televisions.

How do we know the tolerance of a wirewound resistor?

if the value of your resistor is 1,320Ω ± 5%
What is the exact color band in the resistor?

What can be the cause of a malfunction on a resistor?

How can you can you know if it is a good or bad resistor?

how to identify if what is the wattage rating on a particular resistor?

How can you say that you have the right amount of resistor in terms of putting it in a device?

garciarogelio wrote:What is the main function of resistor ?

the main function of resistors in a circuit is to control the flow of current to other components.

How do we know if the resistor are turned into reversed?

What is the reading of the resistor value if the color of the resistor multiplier is turned into silver?
And what are the computation in this part..

What are the major defects in resistor?

If the resistor is out of tolerance....the resistor is anable to use? or it is counted for defective resistor?

What the difference between 5 band and 4 band resistor..
Except in color band..

where the five bands resistor are often used?

Why the small resistor have a small amount of wattage and the large resistor have a high wattage but the resistance of two resistor are same amount?

what are the chemical contents of resistor?

Jaymark23 wrote:What can be the cause of a malfunction on a resistor?

a rate of failure in resistors are very low. But here are the common failure you'll encounter in using resistors.
Short Circuited resistor
Generally a resistor does not become short circuited. But a meter may show short due to some component that is connected across the resistor may get shorted.
Noise in Resistance
Random motion of electrons in a resistor results in noise called White noise. Some noise is normal depending on the value of resistance and temperature. However, bad contacts of end-connectors may cause noise higher than normal.
Irregular contact
Particle of dust, grease between the wiper and resistance material may result in irregular contact and may increase noise.
Dry or Cold Soldering Joint
The dry or cold soldering joint may behave as high resistance leads.

Melyssa120504* wrote:What the difference between 5 band and 4 band resistor..
Except in color band..

I think there's no difference in the said band resistor. You can use it in a circuit either 4 and 5. It just depend on the value you want to use, so you'll chose between the two.

Melyssa120504* wrote:where the five bands resistor are often used?

mostly in a circuit, the same as 4 band resistors.

Jaymark23 wrote:What can be the cause of a malfunction on a resistor?

Resistor failures are considered to be electrical opens, shorts or a radical variation from the resistor specifications. The failure modes experienced vary with the type of construction. A fixed composition resistor normally fails in an open configuration when overheated or overly stressed due to shock or vibration.

Excessive humidity may cause an increase in resistance. A variable composition resistor may wear after extensive use, and worn away particles may cause high resistance short circuits. Wirewound resistors may experience open windings due to overheating or stress, or short circuited windings due to accumulation of dirt, dust, breakdown of the insulation coating or high humidity. Film resistors fail for the same reasons as wirewound and composition, but have also failed due to changes in resistive material characteristics resulting in reduction and increase in resistance value.

Why do resistors heat up?

Why would a resistor overheat?

Do resistors have voltage ratings?

Do resistors in series have the same current?

Why resistor have two terminals?

Melyssa120504* wrote:what are the chemical contents of resistor?

Resistor composition. Resistors can be constructed out of a variety of materials. Most common, modern resistors are made out of either a carbon, metal, or metal-oxide film. In these resistors, a thin film of conductive (though still resistive) material is wrapped in a helix around and covered by an insulating material.

Markdhaniel211 wrote:Do resistors have voltage ratings?

The maximum value of dC voltage or AC voltage (rms) capable of being applied continuously to resistors or element. however, the maximum value of the applicable voltage is the rated voltage at the critical resistance value or lower. Noise is an unwanted AC signal from within the resistor.