Power Formula Voltage Current

Current flowing in the circuit i and resistance r.

Power formula voltage current. For any circuit element the power is equal to the voltage difference across the element multiplied by the current. 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. But we have designed this one especially for dc circuits as well as work for single phase ac circuits without power factor. The product of the voltage and current is the apparent power and measured in va or kva.

In the international system of units the unit of power is the watt equal to one joule per second. Which can also be expressed as. How to use ohm s law to determine current. We ve seen the formula for determining the power in an electric circuit.

Power voltage current resistance p v i r calculator. 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. Power formula 1 electrical power equation. An electric machine makes use of 300 j of energy to do work in 10s.

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. In physics power is the amount of energy transferred or converted per unit time. 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. In older works power is sometimes called activity.

For example in an open circuit condition voltage is present but there is no current flow i 0 zero therefore v 0 is 0 so the power dissipated within the circuit must also be 0 likewise if we have a short circuit condition current flow is present but there is no voltage v 0 therefore 0 i 0. The output power of a motor is the product of the torque that the motor generates and the angular velocity of its output shaft. By ohm s law v ir and so there are additional forms of the electric power formula for resistors. How much power does it use.

If there is ac look also at the power factor pf cos φ and φ power factor angle phase angle between voltage and amperage. Three phase power and current. In the above circuit we know we have a battery voltage of 18 volts and a lamp resistance of 3 ω. The relationship between kva and kw is the power factor pf.

One ohm is defined as the resistance which allows the current of one ampere under a potential difference of 1 volt. The power taken by a circuit single or three phase is measured in watts w or kw. Power is measured in units of watts w where a watt is equal to a joule per second 1 w 1 j s. Power within an electrical circuit is only present when both voltage and current are present.

The standard metric unit of power is the watt. The electrical relationships between resistance r current i power p and voltage e is defined by ohm s law.