Power And Voltage Equation

If there is ac look also at the power factor pf cos φ and φ power factor angle phase angle between voltage and amperage.

Power and voltage equation. We have already expressed the armature current i a of the motor in terms of voltage and resistances during explanation of back emf. The power formula is used to compute the power resistance voltage or current in any electrical circuit. Power equation of a dc motor. To get the result in watts work must be expressed in joules and time must.

The standard metric unit of power is the watt. And that equation was nothing but the voltage equation of the motor. Learn the power formula. Work done w 300 j time taken t 10 s.

Electric power is usually produced by electric generators but can also be supplied by sources such as electric batteries it is usually supplied to businesses and homes as domestic mains electricity by the electric power industry. In this calculator table you may enter two of the four factors in ohm s law. Electric power is the rate per unit time at which electrical energy is transferred by an electric circuit the si unit of power is the watt one joule per second. An electric machine makes use of 300 j of energy to do work in 10s.

We ve seen the formula for determining the power in an electric circuit. Power formula 1 electrical power equation. 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. 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.

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. 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. Voltage equation of dc motor.

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. 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. In the above circuit we know we have a battery voltage of 18 volts and a lamp resistance of 3 ω.