QA

Question: How To Read Resistor Values

How do you decode a resistor?

In the standard four band resistors, the first two bands indicate the two most-significant digits of the resistor’s value. The third band is a weight value, which multiplies the two significant digits by a power of ten. The final band indicates the tolerance of the resistor.

How do you read a resistor label?

Touch one meter probe to the free varistor lead and the other probe to the connected lead. Read the resistance on the meter. If it reads nearly infinite resistance, the varistor is still good. If it reads very low resistance, the varistor is blown.

How do you read a 3 band resistor?

For a 3-band resistor color codes, the first two bands always denote the first two digits of the resistance value while the third band represents the multiplier. In the example we have, the bands are brown, black and brown. The first band is the brown band closest to the edge.

What is the color code for 2.7 K?

2.7K Ohm Resistor Color Code: Red, Violet, Red, Golden.

What is coded value in resistor?

Components and wires are coded with colors to identify their value and function. Resistor Color Coding uses colored bands to quickly identify a resistors resistive value and its percentage of tolerance with the physical size of the resistor indicating its wattage rating.

How do you know if a resistor is positive or negative?

Resistors don’t care which leg is connected to positive or negative. The + means where the positive or red probe of the volt meter is to be placed in order to get a positive reading. This is called the “positive charge” flow sign convention.

What is varistor used for?

Varistors are used to protect a circuit from high voltage surges. When a high voltage surge is applied to a circuit, the outcome is usually catastrophic to the circuit. A capacitor may be installed across the signal lines.

How do voltage dependent resistors work?

A voltage dependent resistor has a nonlinear varying resistance, dependent on the voltage applied. They are often used to protect circuits against excessive transient voltages. When the circuit is exposed to a high voltage transient, the varistor starts to conduct and clamps the transient voltage to a safe level.

How do you read a resistor color code 5?

If the colors on a 5 band resistor is in this order: brown, green, red, blue and violet (as shown in figure). The values of color bands will be like this: Brown = 1, Green = 5, Red = 2, blue = 106, Violet = 0.10%.

Which Colour represents 7 in resistor color code?

Violet Color Significant figures Tolerance Yellow 4 – Green 5 ±0.5% Blue 6 ±0.25% Violet 7 ±0.1%.

What color is a 6.8 K resistor?

Blue Value First Color Third Color 56* Green 5.6 k 62 Blue 6.2 k 68* Blue 6.8 k 75 Violet 7.5 k.

What is the 4th band on a resistor?

The fourth band (or 5th for the 5-band and 6-band) indicates the tolerance values. Here, two colors are added (gold and silver). The 6th band for a 6-band type resistor is the temperature coefficient. This indicates how much the actual resistance value of the resistor changes when the temperature changes.

How can you tell the wattage of a resistor?

A resistor’s power rating can usually be deduced by observing its package size. Standard through-hole resistors usually come with ¼W or ½W ratings. More special purpose, power resistors might actually list their power rating on the resistor. These power resistors can handle a lot more power before they blow.

Do resistors have continuity?

If your resistor is of greater resistance than the threshold on your meter, then even though current can flow through it, the meter will not register continuity. Show activity on this post. The continuity test applies a very small voltage to the circuit and check what current flows through it.

What are the symbols on multimeter?

What are voltage, current, and resistance? Variable Symbol Symbol Voltage V V Current I A Resistance R Ω.

How is a 3.9 K resistor color code?

3.9K Ohm Resistor Color Code: Orange, White, Red, Golden. Resistance: 3.9K Ohm, Power Rating: 1 Watt, Approximate Maximum Current: 16.01mA .

What color is a 680 ohm resistor?

680 Ohm Resistor Color Code: Blue, Gray, Brown, Golden. Resistance: 680 Ohm, Power Rating: 2 Watts, Approximate Maximum Current: 54.23mA ..

What color is a 390 ohm resistor?

390 Ohm Resistor Color Code: Orange, White, Brown, Golden. Resistance: 390 Ohm, Power Rating: 0.25 Watt, Approximate Maximum Current: 25.32mA .

What do the colors on a resistor mean?

The colour code used to denote the tolerance rating of a resistor is given as: Brown = 1%, Red = 2%, Gold = 5%, Silver = 10 % If resistor has no fourth tolerance band then the default tolerance would be at 20%.

What color is a 1k resistor?

Brown, Black, Red, Gold Band Value 1st Brown 1 2nd Black 0 3rd Red 100 4th gold 5%.

How does 4 bands resistor differ from 5 bands?

As we see in the above image a 5 band resistor has an extra digit before you get to the multiplier band, this allows for more precision in describing the value of the resistor which is important as most 5 band resistors are higher precision, having a tolerance of 1% to 2% while 4 band resistors typically have.

What is positive and negative resistance?

While a positive resistance consumes power from current passing through it, a negative resistance produces power. Under certain conditions it can increase the power of an electrical signal, amplifying it.

Do resistors have polarity?

A resistor is a small component that’s designed to provide a specific amount of resistance in an electronic circuit. Resistors are blind to the polarity in a circuit. Thus, you don’t have to worry about installing them backwards. Current can pass equally through a resistor in either direction.

Does a current flow from positive to negative?

The flow of electrons is termed electron current. Electrons flow from the negative terminal to the positive. Conventional current or simply current, behaves as if positive charge carriers cause current flow. Conventional current flows from the positive terminal to the negative.