Power Equation With Voltage And Current

The standard metric unit of power is the watt.

Power equation with voltage and current. Where voltage applied across the two ends v current flowing in the circuit i and resistance r. Electric power like mechanical power is the rate of doing work measured in watts and represented by the letter p the term wattage is used colloquially to mean electric power in watts the electric power in watts produced by an electric current i consisting of a charge of q coulombs every t seconds passing through an electric potential difference of v is. We know that reactive loads such as inductors and capacitors dissipate zero power yet the fact that they drop voltage and draw current gives the deceptive impression that they actually do dissipate power. Power formula 1 electrical power equation.

In a simple alternating current ac circuit consisting of a source and a linear load both the current and voltage are sinusoidal if the load is purely resistive the two quantities reverse their polarity at the same time at every instant the product of voltage and current is positive or zero the result being that the direction of energy flow does not. By multiplying the voltage in volts by the current in amps we arrive at an answer in watts let s apply this to a circuit example. For any circuit element the power is equal to the voltage difference across the element multiplied by the current. Power voltage current resistance p v i r calculator.

Learn the power formula. The power formula is used to compute the power resistance voltage or current in any electrical circuit. By ohm s law v ir and so there are additional forms of the electric power formula for resistors. In this calculator table you may enter two of the four factors in ohm s law.

The watts equation for an electrical circuit takes into account the voltage across the circuit v measured in volts and the current i measured in amps passing through it in mechanics the definition of power is the rate of doing work w it s defined as w t where t is the time it takes for the work to be completed. How to use ohm s law to determine current. We ve seen the formula for determining the power in an electric circuit. This phantom power is called reactive power and it is measured in a unit called volt amps reactive var rather than watts.

If there is ac look also at the power factor pf cos φ and φ power factor angle phase angle between voltage and amperage. In regards to voltage and resistance it is articulated as. Power is measured in units of watts w where a watt is equal to a joule per second 1 w 1 j s. Active reactive and apparent power.

To get the result in watts work must be expressed in joules and time must. 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. Power p i v r i 2 v 2 r where power p is in watts voltage v is in volts and current i is in amperes dc. The mathematical symbol for reactive.