0
All resistors have a rating called 'maximum power dissipation', usually referred to as simply 'power'. Typical values are 1/8 watt, 1/4 watt, 1/2 watt, 1 watt, etc. up to many hundreds of watts for specialized resistors. Basically, if you exceed the power rating for a given resistor, it will fail. If you run it right at maximum power, it will work for a while, but will have a fairly short lifespan and will eventually fail (this is true for all electronic components for the most part). If you run it well below its maximum rating, it will pretty much last forever. Take a 10 ohm, 1 watt resistor and connect it to a 12 volt battery (hypothetically, that is, don't try this at home!) The current through the resistor will be: I=E/R I=12/10 I= 1.2 amperes The power dissipation will be: P=I^2 * R P=1.2^2 * 10 P=14.4 watts A 1 watt resistor that is dissipating 14.4 watts will fail in seconds, accompanied by smoke and quite possibly fire! Now connect a 270 ohm, 1 watt resistor to the 12 volt battery. The current: I=12/270 = 0.044 amperes (44 ma.) The power: P=0.044^2 * 270 = 0.52 watts This resistor will certainly get warm, but is operating well within its power rating and will last a long time.
Wiki User
∙ 15y ago
Add your answer:
Earn +20 pts
Most common failure in a resistor?
This depends on the type of resistor. Carbon composition and metal film resistors typically will burn open, carbon film types can short.
Why put an end resistor in fire detector loop?
Because if you dont you will burn and might get athsma Because if you dont you will burn and might get athsma Because if you dont you will burn and might get athsma
What is my Led and what resistor do I need?
Led is a light emitting diodes which can two leads .one lead is larger and the other is smaller. You did't use any resistor because it glows with the small amount of energy! Idiot. I mean't how to I find out what my LED is. I know what a Led is and without a resistor, you prick, It wouldnt last a second.
Why resistor should disconnected from the circuit when measured the value of resistor?
if not disconnected you will measure the resistance of the circuit in parallel with the resistor.
What does the resistance in an electrical circuit limit?
Current flow. It's also worthy of noting that a resistor doesn't limit-by, it limits-to, and the current is dependent on the voltage. I[A] = U[V] / R[ohm] It's also worth to note, that the power flowing through said resistor with resistance R is I[A] * U[V] for DC circuits - helps to remember this well when picking appropriately-rated resistors for replacement. Example: let's say we have a 20-ohm, 2W resistor. If we place it in a circuit with 5V, we will get 5V / 20ohm = 250mA (0.25A) of current flowing through the resistor. The power the resistor will "see" is 250mA * 5V = 1.25W, so it's safe. But let's now put that same resistor in a 12V circuit. The current flowing will be 12V / 20ohm = 600mA (0.6A), and the power will be 600mA * 12V = 7.2W, so the resistor will burn.
At what level will typical resistors burn out?
A typical resistor will burn out when it dissipates power in excess of double its power dissipation rating for an extended period of time. The power dissipated by a resistor is equal to I2R or E2/R, where E = the voltage across the resistor I = the current through the resistor R = the resistance of the resistor
Most common failure in a resistor?
This depends on the type of resistor. Carbon composition and metal film resistors typically will burn open, carbon film types can short.
Why put an end resistor in fire detector loop?
Because if you dont you will burn and might get athsma Because if you dont you will burn and might get athsma Because if you dont you will burn and might get athsma
Your car was leaking water on the resistor so you fixed the leak and replaced the resistor and in the mean time before the resistor got replace the fan would only kick on on the highest setting but on?
The old resistor was burned out. If you burn out the new one again, replace the blower motor.
Why does resistor burn up?
cause its bad,replace with higher wattage rating.too much current !!
Will bad ballast resistor on a 1978 D100 make engine die?
Yes it can. If there is a bad wire in your harness the ballast resistor will get hot, in which causes your coil to overheat and cut out or burn outline.
Resistor blower jeep wrangler cable burn up now I dont know how to put the wire back together you have four pin dark green green brown can some body help out?
the year of the jeep is 1997 since the harness clip burn (i dont have the clip).. i dont know how to put cable back to the resistor it has 4 wire. from left to right please tell me which color goes were on the harness thank you You have got to say what year this is for. Not all years are the same. Thnks.
How do you know if the blower motor resistor is bad?
A malfunctioning blower motor resistor will cause the blower motor not to work. When the resistor is bad the blower motors will not turn on.
Why do resistors burn out?
Most often a resistor fails because it is unable to properly dissipate the heat generated by the current flow. A resistor rated for more power (higher wattage) may resolve the problem.
Why wouldn't the shunt resistor in the ammeter protect the ammeter when the ammeter is connected in parallel?
Connecting an ammeter in parallel subjects that ammeter to the full supply voltage. The shunt resistor is not designed to sustain that value of voltage and will burn out. Also, the clue is in the word 'shunt' (which means 'in parallel') which means that the coil will also burn out!
Air wont blow hard in truck anymore?
If it's a fan speed issue check the blower motor resistor & the blower motor. Check the plugs at the resistor and blower motor for burn marks also.
What resistor should you use to get 9v to 6v?
You can only use a resistor to drop a voltage at a constant current. If you know the current, use Ohm's law to calculate the resistor value.
