# Power formula in terms of current and resistance

Mar 22, 2017 · Relationship between Energy Transferred, Current, Voltage and Time The potential difference or voltage, V across two points is defined as the energy, E dissipated or transferred by a coulomb of charge, Q that moves through the two points. Therefore, potential difference, Current is the rate of charge flow.

In electronics the effect is usually negligible, but if the resistance is low (a wire or low value resistor for example) the current can be sufficiently large to cause a problem. You can see from the equation P = I² × R that for a given resistance the power depends on the current squared, so doubling the current will give 4 times the power. Apr 30, 2019 · The power value P used in these formulas refers to instantaneous power, or power at a specific moment in time. If the circuit uses AC power, the power is changing constantly. Electricians calculate the average power for AC circuits using the formula P average = VIcosθ, where cosθ is the power factor of the circuit.

May 15, 2018 · Since active power = VICosØ and apparent power = VI, it can be calculated by calculating the ratio of Active Power and Apparent Power. The formula for pf in terms of active and apparent power is given as; pf = Active Power / Apparent Power. Power Factor for Resistance, Capacitor and Inductor: Because power is a function of voltage multiplied by current, and both voltage and current doubled from their previous values, the power will increase by a factor of 2 x 2, or 4. You can check this by dividing 432 watts by 108 watts and seeing that the ratio between them is indeed 4. In electronics the effect is usually negligible, but if the resistance is low (a wire or low value resistor for example) the current can be sufficiently large to cause a problem. You can see from the equation P = I² × R that for a given resistance the power depends on the current squared, so doubling the current will give 4 times the power.

Current, Voltage and Power. Electricity is the flow of electric charge. We can describe the flow of electric charge in several ways. These include the quantities Current, Voltage and Power. Current. Current (I) is the rate of flow of Charge Carriers, such as electrons. Apr 24, 2017 · Since power, measured in watts, is a function of voltage and current, and current is a function of voltage and resistance, it is possible to calculate resistance from power and voltage. The calculations are simple but an understanding of simple math is advantageous. Power in mechanical systems is the combination of forces and movement. In particular, power is the product of a force on an object and the object's velocity, or the product of a torque on a shaft and the shaft's angular velocity. Mechanical power is also described as the time derivative of work. The electrical relationships between resistance (R), current (I), power (P) and voltage (E) is defined by Ohm's Law. One ohm is defined as the resistance which allows the current of one ampere under a potential difference of 1 volt.