0
The voltage drop across a resistor is calculated using Ohm's Law. For a DC or direct current circuit then
V=IR where V is voltage in volts, I is current in amperes, and R is resistance in ohms
If this is a DC circuit the voltage drop is 3A*3ohm=9V
Wiki User
∙ 15y ago
Wiki User
∙ 9y agoI'm assuming you want to know what the current is at a given voltage through a 9 ohm load.
You need to put an ampmeter in series with the 9 ohms. To do this, disconnect one end of the speaker and put one lead on the terminal of the speaker you just disconnected and the other lead connects to where the speaker was connected. Make sure the meter is on the HIGHEST CURRENT setting to start. The reading will be in amps.
I could go into all the math here but I'll just give you the simplified answer on how to determine power which is measured in Watts. Measure the highest voltage across (positive lead of a voltmeter on one end of the 9 ohm load and the negative lead on the other end with the speaker still connected). Crank it up as loud as you like, take the highest voltage reading you get (the meter reading will be bouncing up and down here). Now square the voltage reading and divide it by 9. This will give you the power output in Watts.
FYI. Listen carefully here, WATTS ARE WATTS AND NOTHING ELSE!! There is no such thing as Watts RMS. This has been so misleading that many manufacturers now use the term "Program Power" instead of Watts RMS to determine power ratings. RMS is a term that only applies to voltage and current. Although voltage times amps equals watts, RMS does not apply to power disapation. Even though its stamped on the back of most amplifiers and bragged about by many a sales person its a misnomer.
Comment
As the original answer states, there is no such thing as 'r.m.s. watts'; it is simply the product of an r.m.s. voltage and an r.m.s. current. It is used by hi-fi amplifier companies to give a meaningful value to the output power of an amplifier. Cheap and nasty amplifiers are rated in 'maximum watts', which are quite meaningless.
Add your answer:
Earn +20 pts
Two resistors are connected to a 9 volt battery the larger one provides twice as many ohms as the small one the current through the circuit is 3 amps what is resistance of larger resistor?
If the two resistors are in series, then the larger one is 2 ohms.(The smaller one is 1 ohm. Their combined series total is 3 ohms. 9/3 = 3 amps.)If the two resistors are in parallel, then the larger one is 9 ohms.(The smaller one is 4.5 ohms. The combined parallel total is 3 ohms. 9/3 = 3 amps.)
What is 95kV in amps?
You can't convert kV (kilovolts) to current (amps) unless you know the resistance (ohms) of the load which is taking current from that voltage source. Once you know the resistance then you can use Ohm's Law to get the amperage: I = V / R In words, Ohm's law is: Current (amps) equals voltage divided by resistance (ohms)
How much resistance required to convert 12V DC to 10.5V DC?
How much current? Volts/Amps = Ohms. In your case Volts = 1.5
What effect are there when resistance is increased in the size of the current?
Current is inversely proportional to resistance. If you double the resistance, you halve the current. Ohm's Law: Volts = Amps * Ohms Solve for Amps: Amps = Volts / Ohms
What area of science uses amps and ohms?
Amps, or amperes, are a measure of electrical current; ohms are a measure of electrical resistance. Both are widely used in physics.
Convert 1000 ohms to amps?
Can not do it without knowing the voltage I = E/R. Amps = Voltage/Ohms.
If voltage is 12 volts and ohms is 0.5 how many amps in circuit?
Ohm's law: Volts = Amps * Ohms, or Amps = Volts / Ohms 12 volts / 0.5 ohms = 24 amps
Formula for ohms law?
ohms=amps/volts Amps= volts/ohms Volts = Amps*Ohms
Two resistors are connected to a 9 volt battery the larger one provides twice as many ohms as the small one the current through the circuit is 3 amps what is resistance of larger resistor?
If the two resistors are in series, then the larger one is 2 ohms.(The smaller one is 1 ohm. Their combined series total is 3 ohms. 9/3 = 3 amps.)If the two resistors are in parallel, then the larger one is 9 ohms.(The smaller one is 4.5 ohms. The combined parallel total is 3 ohms. 9/3 = 3 amps.)
How do you find OHM?
Ohms can be found by using these formulas. Ohms = Volts/Amps, Ohms = (Volts (squared))/Watts, Ohms = Watts/(Amps (squared)).
3 kilo ohms times 3 micro ohms equals?
You have to convert all values to ohms. 3 kiloohms = 3000 ohms. 3 micoohms = three millionth of an ohm = 0.000003 ohms. The product is: 3000 times 0.000003 = 0.009 ohms squared.
How do you calculate ohms?
Very basically, simply divide the voltage by the amperage. Thsi is not for calculating Ohms of resistance, just Ohms. For example, a 9 volt battery that delivers 3 amps has 3 ohms. To calculate ohms of resistance we use the ohms law. This measures the difference in current flow in amps (amps/current is amount or volume of flow, volts is power pushing that current, sort of) and voltage. For instance, measure the amps and voltage at the source and record the ohms. Then record the same at the end point the difference in ohms is ohms of resistance. So, if we measure 10 volts and 2 amps at the source we have 5 ohms. at the end point we have 8 volts and 1 amp we have 8 ohms. therefore we have 13 ohms of resistance. 1 Determine current. Current is the flow of electricity measured in amps. For example a current has four amps in the circuit. 2 Determine voltage. Voltage is the difference in electrical potential from two points, measured in volts. For example, there is two-hundred volts in a circuit. 3 Divide voltage by current to calculate resistance. Resistance is measured in ohms. In the example, two-hundred volts divided by four amps equals fifty ohms. 4 To get ohms of resistance, measure the end point. at the endpoint we have 100 volts and 2 amps=50 ohms. therefore we have 100 ohms of resistance
9 volt baterry produce 3 amperes 3ohms 6 ohms 9ohms 27 ohms?
U=RxI U/R=1 9 volts/3 ohms=3 amps
How many things are needed to have current?
3 things Volts, ohms, and amps
How do you work out the current?
There are three formulas that you can use. Amps = Volts/Ohms Amps = Watts/Volts Amps = sq root of Watts/Ohms
What is the voltage of an appliance that has a current of 3 amps and a resistance of 4 ohms?
12 volts.
What is 95kV in amps?
You can't convert kV (kilovolts) to current (amps) unless you know the resistance (ohms) of the load which is taking current from that voltage source. Once you know the resistance then you can use Ohm's Law to get the amperage: I = V / R In words, Ohm's law is: Current (amps) equals voltage divided by resistance (ohms)
