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You need a resistor rated to dissipate 12 watts (P = I^2 * R).
You may be hard pressed to find locally, I would suggest using www.mouser.com. There is a part 280-CR15-12-RC (15 watt, 12 ohm 5% resistor) for $.63 (US). Mouser has a lot of parts, this is just the first that popped up in my search, so you should be able to find whatever you need (I use this site when prototyping).
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What resistor to use to drop 9volt's dc to 6 volt's dc?
To drop a 12 volt source to 6 volts with a resistor, you have to drop 6 volts. The value of the resistor you need would be 6 divided by the current the device pulls in amps. For example, if the device pulls a half an amp the resistor has to be 6/0.5 or 12 ohms. As this device runs on 6 volts and draws 1/2 amp, it's wattage is 3 watts (volts x Amps). Common practice is to double this, or the resistor will probably get too hot and may open. I'd use a 10 watt to resistor to maintain a good margin for safety, and they're readily available. Use a 12 ohm, 10 watt resistor.
What will be the amps of a 12v 2amp circuit if there is a 12ohm resistor on it?
The formula you are looking for is I = E/R. Amps = Volts/Resistance. If you say it is normally a 2 Amp circuit, it normally draws 2 amps. Therefore the original resistance offered to the 12v battery is 2/12 = 6 Ohms. If you then connect a 12 Ohm resistor in series, they are added, so R = 18 Ohms. Now if you put 12v across this circuit it will draw 12/18 = 0.66 Amps. Or If you just put a 12 Ohm resistor across the 12v supply it will draw 1 Amp. If the circuit is protected by a 2 Amp fuse, it will not blow, but the resistor will get hot.
What resistor to drop 2V to 1 1.5V?
Doing it with a single resistor is not a good idea because it can only be done with exactly the right amount of current. If the current is 1 amp, for a voltage drop of 10.8 volts you need 10.8 ohms (volts/amps).
If three cells that each have an emf 1.5 volts and an internal resistance of 2 ohms are connected in series to a resistor of 44 ohms what is the current through the resistor?
Taking the question at face value, the internal resistances will be treated like "real" resistors in the circuit. That means we have 3 batteries of 1.5 volts each connected in series with their 2 ohms + 2 ohms + 2 ohms of internal risistance, or 6 ohms of internal resistance. The 6 ohms of internal resistance acts in series with the 44 ohms of resistance stated as the value of the resistor. The total resistance is simply the sum of the two, or 6 ohms + 44 ohms or 50 ohms of total resistance. The batteries are connected in series, and their individual voltages are added to find total applied voltage. That means 1.5 volts + 1.5 volts + 1.5 volts or 4.5 volts will be the total applied voltage. Total current in the circuit (and through our 44 ohm resistor) will be the voltage applied divided by the resistance ( I = E / R), which, in this case, is 4.5 volts / 50 ohms which equals 0.07 amps. That's 7/100ths of an amp, or, in electronics speak, 70/1000ths of an amp, or 70 milliamps, or 70mA of current. The circuit is a series circuit, and that current, the total circuit current, will be flowing through each and every component of the circuit. That's what a series circuit means.
How To Measure Electrical Resistance?
If you put a current of 1 amp through a resistor, the voltage across it is equal to the resistance in ohms. This can also be done with lower currents and then the result must be multiplied up in the right ratio. An ohmmeter, or the ohm scale on a multimeter, uses a battery to supply the current.
What is the voltage difference across a 30- resistor if a 0.5 amp current is flowing through it?
30 ohms x 0.5 amp, that is 15 v.
What size resistor to drop 9 dc to 3 dc at 1 amp?
330 milli ohms
How much power is consumed through a 3 amp?
-- If the 3 Amp is being drawn from a battery,then the battery is supplying3 x (Voltage of the battery) watts.-- If the 3 Amp is flowing through a resistor,then the resistor is dissipating9 x (Resistance of the resistor) watts.
What resistor to use to drop 9volt's dc to 6 volt's dc?
To drop a 12 volt source to 6 volts with a resistor, you have to drop 6 volts. The value of the resistor you need would be 6 divided by the current the device pulls in amps. For example, if the device pulls a half an amp the resistor has to be 6/0.5 or 12 ohms. As this device runs on 6 volts and draws 1/2 amp, it's wattage is 3 watts (volts x Amps). Common practice is to double this, or the resistor will probably get too hot and may open. I'd use a 10 watt to resistor to maintain a good margin for safety, and they're readily available. Use a 12 ohm, 10 watt resistor.
How to wire and amp down to 0.3 ohms?
You can wire and amp down to 0.3 ohms by decreasing its windings.
What will be the amps of a 12v 2amp circuit if there is a 12ohm resistor on it?
The formula you are looking for is I = E/R. Amps = Volts/Resistance. If you say it is normally a 2 Amp circuit, it normally draws 2 amps. Therefore the original resistance offered to the 12v battery is 2/12 = 6 Ohms. If you then connect a 12 Ohm resistor in series, they are added, so R = 18 Ohms. Now if you put 12v across this circuit it will draw 12/18 = 0.66 Amps. Or If you just put a 12 Ohm resistor across the 12v supply it will draw 1 Amp. If the circuit is protected by a 2 Amp fuse, it will not blow, but the resistor will get hot.
Can you connect 2 amps to run a subwoofer?
If your sub is 2 ohms and your amp is 2 ohm stable, your done. Your amp will be at 2 ohms because the sub is 2 ohms.
What is a 1.5 omega resister?
The capital Greek letter Ω (omega) is the symbol for Ohms - the unit of resistance. A 1.5Ω resister is a resistor with quite a low resistance. If a voltage of 1.5 Volts is applied across it, a current of 1 Amp[ere]s will flow through it.
What resistor to drop 2V to 1 1.5V?
Doing it with a single resistor is not a good idea because it can only be done with exactly the right amount of current. If the current is 1 amp, for a voltage drop of 10.8 volts you need 10.8 ohms (volts/amps).
If three cells that each have an emf 1.5 volts and an internal resistance of 2 ohms are connected in series to a resistor of 44 ohms what is the current through the resistor?
Taking the question at face value, the internal resistances will be treated like "real" resistors in the circuit. That means we have 3 batteries of 1.5 volts each connected in series with their 2 ohms + 2 ohms + 2 ohms of internal risistance, or 6 ohms of internal resistance. The 6 ohms of internal resistance acts in series with the 44 ohms of resistance stated as the value of the resistor. The total resistance is simply the sum of the two, or 6 ohms + 44 ohms or 50 ohms of total resistance. The batteries are connected in series, and their individual voltages are added to find total applied voltage. That means 1.5 volts + 1.5 volts + 1.5 volts or 4.5 volts will be the total applied voltage. Total current in the circuit (and through our 44 ohm resistor) will be the voltage applied divided by the resistance ( I = E / R), which, in this case, is 4.5 volts / 50 ohms which equals 0.07 amps. That's 7/100ths of an amp, or, in electronics speak, 70/1000ths of an amp, or 70 milliamps, or 70mA of current. The circuit is a series circuit, and that current, the total circuit current, will be flowing through each and every component of the circuit. That's what a series circuit means.
How can you work out the power of a resistor?
It depends what you mean by your question. Ohms Law is the key. Power in a resistor is wasted as heat. If a resistor has 1 volt across it and passes a current of 1 amp, it will consume/dissipate one Watt of power ,and must therefore have a resistance of one ohm. To work out the power rating of a resistor required, use V x I = P V is voltage I is current in Amps P is power in Watts R is resistance in ohms V=I X R. I=V/R R=V/I Ohms Law is the fundamental equation of electricity and must be understood before you can go further.
Who is law states that it takes one volt to push one amp through 1 ohm of resistance?
Ohms Law.
