While both kVA and kW are units of measure, kVA is a kilo volt amperes and kW is a kilowatt. Both the kVA and the kW are units used to express power.Know More
kVA is known as the apparent power of an electrical system or of a particular circuit. In direct current circuits the kVA is equal to the kW because the current and the voltages do not get out of phase. However, "real power" and "apparent power" differ in their alternating current circuits so kW is the amount of actual power that does valid work where only a fraction of kVA is available and accessible to do work while the rest is in excess in the current.
The relationship between kVA, kW and the power factor is described mathematically as: kW = kVA x power factor; kVa = kW/power factor; and power factor = kW/kVA. In DC circuits, there is no difference between the kVA and the kW because of the power factor. The power factor leads or lags depending on the way that the load shifts the phase of the current compared to the phase of the voltage. This creates a unity in the DC circuits. In AC circuits, voltage and current may get out of phase leading to a difference in kW and kVA that will be based on the power factor (or how much leading or lagging occurs).Learn more about Electricity
The difference between a cell and a battery is that a cell is a single unit that converts chemical energy into electrical energy, and a battery is a collection of cells. According to About.com expert Mary Bellis, each cell contains two electrodes and an electrolyte, a substance that reacts chemically with each electrode, generating an electrical current. Aggregating cells into a battery increases the electrical voltage they produce.Full Answer >
Relays are usually cheaper and lower in their performance capabilities for signal switching and load handling than contactors. While contactors and relays are both used in engineering applications to switch signals and power connections, relays are used in applications where speed and power are not as critical.Full Answer >
The primary difference between lap winding and wave winding is the current (amperage) and voltage requirements of the generators. Generators requiring a high current with low voltage use lap winding. For a low current and high voltage, generators use wave winding. Both types of winding are required for direct current generators.Full Answer >
The difference between a BJT, or bipolar junction transistor, and an FET, or field effect transistor, lies in its control and polarity; BJT is bipolar and FET is unipolar. A BJT is primarily controlled by current, while an FET is mainly controlled by voltage.Full Answer >