Calculate the impedence of your 3V circuit in ohms. Figure the voltage you want to drop. In this case, you need to lose 9V. This is three times the voltage you are supplying, so the resistor should have three times the resistence of your 3V circuit. If your circuit has 100 ohms of resistence (impedence), then you would connect a 300 ohm resistor in series with your circuit.
Depends on the led forward bias threashold, if its a typical led it will be .7 volts so, .7x6=4.2V, so pick a resistor that will drop around 7 volts. What is the current? Then just to V=IR, 7=IR.
No. Your power supply must be able to supply rated voltage (12 volts) and rated current (3 amps).
only way to convert from 3 phase to 240 would be to change the electric motor on the compressor
Two 3-ohm resistors in parallel have an effective resistance of 1.5 ohms.I = E/R = 12/1.5 = 8 AmperesNote: Use big resistors. The power dissipated by each resistor is E2/R = 48 watts !
When two 4-ohm resistors are connected in parallel across 12 volts:-- Each resistor has 12V across it, so the current is I = E/R = 12/4 = 3 amperes.-- The total current from the battery is 6 amperes.-- The effective resistance as seen by the battery is R = E/I = 12/6 = 2 ohms.-- If you didn't know the voltage of the battery, you would calculate theeffective resistance of the parallel resistors in advance like this:1/R = 1/4 + 1/4 = 1/2R = 2 ohms.When you connected them to a battery, the battery would agree.
The answer depends on what you wish to convert it to. One possibility is 12-9 = 3
difference is 2.7 amperes in numbers will be 12 volts 3 amps and the other will be 12 volts .3 amps
There is insufficient information in the question to properly answer it.You need to specify if the resistors were in series or parallel.Also, it is incorrect to say "current ... across" - it must be "current ... through".Assuming that you mean a series circuit then it can be solved:R(total) = Sum of the resistors in seriesR(tot) = 3 x 4 Ohm= 12 OhmOhm's Law:V = IRV = 42 x 12= 504 Volts(Note: Because Ohm, Volt and Ampere were named after scientists they are always given capital letters. Ohm not ohm)
The current in the circuit will depend on how the three resistors are wired. Series? Parallel? Series parallel? With the resistors in series, 3, 2 and 4 ohms will add to 9 ohms. As I = E/R, I = 9 V / 9 ohms = 1 A. With the resistors in parallel, the 3, 2 and 4 ohm resistors will draw 3 A, 4.5 A and 2.25 A respectively, and the total current will be the sum of the branch currents, or 3 A + 4.5 A + 2.25 A = 9.75 A. There are 3 different series parallel circuits possible, and more investigation will be necessary to solve for them.
Connect three 12 volt batteries in series. You will triple the amperage but the volts will remain at 12. Click the link
The combined resistance is 7.6049 ohms.
Yes connect all 3 batteries in series. 6+6+12=24 volts.