What is power rating in resistor?

What is power rating in resistor?

The power rating of a resistor indicates how much power a resistor can handle before it becomes too hot and burns up. Power is measured in units called watts. The more watts a resistor can handle, the larger and more expensive the resistor is. Most resistors are designed to handle 1/8 W or 1/4 W.

What is tolerance and power rating of resistor?

The power rating of a resistor is the specification given with a resistor that serves to tell the maximum amount of power that the resistor can withstand. Thus, if a resistor has a power rating of 1/4 watts, 1/4 watts is the maximum amount of power that should be fed into the resistor.

What are the two power ratings of a resistor?

The power rating of a resistor is measured in watts, and it’s usually somewhere between ⅛W (0.125W) and 1W. Resistors with power ratings of more than 1W are usually referred to as power resistors, and are used specifically for their power dissipating abilities.

Why is power rating important?

Resistor power rating is an important parameter to consider when choosing a resistor for a particular application. The job of a resistor is to resist current flow through a circuit and it does this by dissipating the unwanted power as heat.

How do you calculate the power rating?

Calculate power rating in KVA when you know voltage and output resistance. Use the formula: P(KVA) = (V^2/R)/1000 where R is resistance in ohms. For example, if V is 120 volts and R is 50 ohms, P(KVA) = V^2/R/1000 = (14400/50)/1000 = 288/1000 = 0.288 KVA.

How do I choose a power rating?

It can be found in the user manual for the piece of equipment, printed on the transformer for the appliance, or stamped on the information sticker that is attached to the appliance. Multiply the value for the current by the value for the voltage to determine the power rating.

What does 5% tolerance mean?

Tolerance Band Tolerance is the percentage of error in the resistor’s resistance, or how much more or less you can expect a resistor’s actual measured resistance to be from its stated resistance. A gold tolerance band is 5% tolerance, silver is 10%, and no band at all would mean a 20% tolerance.

How is rated power calculated?

What is the rating of the power?

Power is measured in watts and is the product of volts and amperes. The example above would have a rating of 690 watts. Power rating. In electrical engineering and mechanical engineering, the power rating of equipment is the highest power input allowed to flow through particular equipment.

Do resistors have a voltage rating?

The power rating and voltage rating of a resistor are one common source of confusion. This far exceeds the power rating of the part. Conversely, for high resistance values, the amount of electrical energy that the 0603 resistor can withstand is determined by the working voltage rating of 75 volts.

What are the power ratings of different resistors?

The chart below presents the power rating of different resistors and their sizes. Remember that actual size may vary. 1/8 Watt Resistor – 1.8 x 3 x 28: It handles 13.88 mA when connected to 9 V source. 1/4 Watt Resistor – 2.5 x 6.5 x 28: It handles 27.77 mA when connected to 9 V source.

What are the different sizes of axaxial resistor?

Axial Resistor Sizes Power rating Body length (l) Body diameter (d) Lead length (a) Lead diameter (da) Watt mm mm mm mm 1/8 (0.125) 3.0 ± 0.3 1.8 ± 0.3 28 ± 3 0.45 ± 0.05 1/4 (0.25) 6.5 ± 0.5 2.5 ± 0.3 28 ± 3 0.6 ± 0.05 1/2 (0.5) 8.5 ± 0.5 3.2 ± 0.3 28 ± 3 0.6 ± 0.05

What happens if you exceed the wattage of a resistor?

If this wattage of power is exceeded, the resistor may not be able to withstand the power and may melt and can create a short in a circuit, which can lead to even greater hazards for the circuit. Let’s now define power so that we know exactly what is meant when power is talked about.

How do I choose the right resistor?

Always choose a resistor with a higher power rating than the power being used in the circuit so that the resistor isn’t destroyed by excess heat; this would only serve to cause other hazards or malfunctions in the circuit. The common standard power ratings of resistors are 0.25W, 0.5W, 1W, 2W, 5W, and 25W.