Power Formula Voltage

We ve seen the formula for determining the power in an electric circuit.

Power formula voltage. In older works power is sometimes called activity. For any circuit element the power is equal to the voltage difference across the element multiplied by the current. 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. Power is a scalar quantity.

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. The ampere or amps is the amount of electricity used. Power formula 1 electrical power equation. The number of watts is equal to amps multiplied by volts.

How much power does it use. In the above circuit we know we have a battery voltage of 18 volts and a lamp resistance of 3 ω. The output power of a motor is the product of the torque that the motor generates and the angular velocity of its output shaft. To determine the wattage use a simple multiplication formula.

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. In physics power is the amount of energy transferred or converted per unit time. This page shows you the dc power formula to calculate the power in a given circuit using the values of voltage and ampere. 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.

If there is ac look also at the power factor pf cos φ and φ power factor angle phase angle between voltage and amperage. By ohm s law v ir and so there are additional forms of the electric power formula for resistors. Work done w 300 j time taken t 10 s. 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. Learn the power formula. But we have designed this one especially for dc circuits as well as work for single phase ac circuits without power factor. It is given as p vi where p power v voltage i current.

You will need to know the amps and the volts in the power source. The power formula is used to compute the power resistance voltage or current in any electrical circuit. Determine the watts in a power source. An electric machine makes use of 300 j of energy to do work in 10s.

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. Power voltage current resistance p v i r calculator. Voltage measures the force or pressure of the electricity. How to use ohm s law to determine current.

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.