What is the formula for power in a circuit?
A circuit element dissipates or produces power according to P=IV, where I is the current through the element and V is the voltage across it. Since the current and the voltage both depend on time in an ac circuit, the instantaneous power p(t)=i(t)v(t) is also time dependent.
What is Circuit formula?
Rtot = 8 Ω Now the Ohm’s law equation (ΔV = I • R) can be used to determine the total current in the circuit. In doing so, the total resistance and the total voltage (or battery voltage) will have to be used.
What is the formula for power in watts?
The formula for calculating wattage is: W (joules per second) = V (joules per coulomb) x A (coulombs per second) where W is watts, V is volts, and A is amperes of current. In practical terms, wattage is the power produced or used per second.
What is the efficiency formula?
Efficiency is often measured as the ratio of useful output to total input, which can be expressed with the mathematical formula r=P/C, where P is the amount of useful output (“product”) produced per the amount C (“cost”) of resources consumed.
What is Ampere formula?
Since power is defined as the product of current and voltage, the ampere can alternatively be expressed in terms of the other units using the relationship I = P/V, and thus 1 A = 1 W/V. Current can be measured by a multimeter, a device that can measure electrical voltage, current, and resistance.
What is the formula for current?
Current is usually denoted by the symbol I. Ohm’s law relates the current flowing through a conductor to the voltage V and resistance R; that is, V = IR. An alternative statement of Ohm’s law is I = V/R.
How do you simplify a circuit?
Strategy for simplifying a resistor networkBegin as far away as possible from the circuit location in question.Replace series or parallel resistors with their equivalent resistor.Continue, moving left until a single equivalent resistor represents the entire resistor network.
What is the power in a circuit?
Electrical Power, ( P ) in a circuit is the rate at which energy is absorbed or produced within a circuit. The quantity symbol for power is P and is the product of voltage multiplied by the current with the unit of measurement being the Watt ( W ).
How do I calculate kVA?
Calculation with line to line voltageS(kVA) = √3 × I(A) × VL-L(V) / 1000.So kilovolt-amps are equal to √3 times amps times volts divided by 1000.kilovolt-amps = √3 × amps × volts / 1000.kVA = √3 × A ⋅ V / 1000.S = √3 × 12A × 190V / 1000 = 3.949kVA.
What is kWh formula?
A kilowatt-hour, expressed as kWh or kW·h, is a measure of energy that is equivalent to 1,000 watts of power for a 1-hour time period. Thus, to convert watts to kilowatt-hours, multiply the power in watts by the number of hours, then divide by 1,000. For example: let’s find the kWh of 1,500 watts for 2.5 hours.
How do you calculate total power?
The SI unit of power is the watt, where 1 watt = 1 joule per second. Back to our circuit! To use the power rule (P = I × V), we need to know both the current through the resistor, and the voltage across the resistor. First, we use Ohm’s law ( V = I × R ), to find the current through the resistor.
What is thermal efficiency formula?
So, for a boiler that produces 210 kW (or 700,000 BTU/h) output for each 300 kW (or 1,000,000 BTU/h) heat-equivalent input, its thermal efficiency is 210/300 = 0.70, or 70%. This means that 30% of the energy is lost to the environment. An electric resistance heater has a thermal efficiency close to 100%.