Power From Voltage And Resistance

V v i a r ω.

Power from voltage and resistance. Voltage is represented in equations and schematics by the letter v. When describing voltage current and resistance a common analogy is a water tank. The power p in watts w is equal to the voltage v in volts v times the current i in amps a. Influare international ampere or intensity and r resistance.

P i v. The voltage v in volts v is equal to the square root of the power p in watts w times the resistance r in ohms ω. V i r and the power law equation formula. The amount of current in a circuit depends on the amount of voltage and the amount of resistance in the circuit to oppose current flow.

But we have designed this one especially for dc circuits as well as work for single phase ac circuits without power factor. Power voltage current resistance p v i r calculator. Generally electrical power is dissipated in the form of heat heaters mechanical work such as motors energy in the form of radiated lamps or as stored energy batteries. The voltage v in volts v is equal to the power p in watts w divided by the current i in amps a.

As electrical power is the product of v i the power dissipated in a circuit is the same whether the circuit contains high voltage and low current or low voltage and high current flow. So for this analogy remember. Ohm s law equation formula. Power in a resistance is always positive regardless of voltage polarity and current direction.

V voltage electric potential difference δ v or e electromotive force emf voltage. In this analogy charge is represented by the water amount voltage is represented by the water pressure and current is represented by the water flow. This calculator is based on simple ohm s law as we have already shared ohm s law p i v r calculator in which you can also calculate three phase current. Just like voltage resistance is a quantity relative between two points.

For very low values of resistance for example milli ohms mω it is sometimes much easier to use the reciprocal of resistance 1 r rather than resistance r itself. The power used or dissipated by a resistor can be found using the formula v ir. P power i or j latin. The nominal impedance z 4 8 and 16 ohms loudspeakers is often assumed as resistance r.

They are power p or w measured in watts voltage v or e measured in volts current or amperage i measured in amps amperes and resistance r measured in ohms. For this reason the quantities of voltage and resistance are often stated as being between or across two points in a circuit. In this calculator table you may enter two of the four factors in ohm s law.