Power Vs Current Formula

1 ft lb f 1 356 nm.

Power vs current formula. In physics power is the amount of energy transferred or converted per unit time. Active power in dc circuits. How to use ohm s law to determine current. Power voltage current resistance p v i r calculator.

If there is ac look also at the power factor pf cos φ and φ power factor angle phase angle between voltage and amperage. Resistance if the electric power and the total resistance are known then the current can be determined by using the following formula. Ampere a watt w ohm ω where p is the electric power. 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.

T ftlb torque lb f ft. Learn the power formula. For any circuit element the power is equal to the voltage difference across the element multiplied by the current. In other words there is no frequency f or power factor in dc circuits.

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. This phantom power is called reactive power and it is measured in a unit called volt amps reactive var rather than watts. In older works power is sometimes called activity. T inlb torque in lb f.

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. But we have designed this one especially for dc circuits as well as work for single phase ac circuits without power factor. The output power of a motor is the product of the torque that the motor generates and the angular velocity of its output shaft. We ve seen the formula for determining the power in an electric circuit.

In dc circuits power supply to the dc load is simply the product of voltage across the load and current flowing through it i e p v i because in dc circuits there is no concept of phase angle between current and voltage. P hp horsepower delivered by the electric motor hp. This formula is derived from ohm s law. In the above circuit we know we have a battery voltage of 18 volts and a lamp resistance of 3 ω.

The mathematical symbol for reactive. 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. Electrical motor power velocity and torque equations. T ftlb p hp 5252 n 1b.

I p r corresponding units. By ohm s law v ir and so there are additional forms of the electric power formula for resistors. Power is measured in units of watts w where a watt is equal to a joule per second 1 w 1 j s. In the international system of units the unit of power is the watt equal to one joule per second.

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. Power is a scalar quantity. N revolution per minute rpm alternatively.