Find solution
What's the difference between amps and watts?

What is the difference between Volt/Amps (V*A) and Watts???....both are related to the power equation. P=VA?

  • This is related to electrical power supplies that are often rated in volt*amps. While electrical equipment like video cameras are rated in Watts. Both Watts and V*A seem the same from the equation P=I*E. Why not just use only Watts or only V*A ?

  • Answer:

    VA (volt-amps) is used on AC equipment that is reactive - like transformers - to show the maximum load on the utility line. This is done because reactive loads can have current flowing in and out of them - apparent power - but not necessarily use any real power. Nevertheless, the feed has to be sized to the apparent power. VA and watts are related by the power factor. PF = W/VA If I and V are perfectly in phase (as for a non-reactive load), the power factor is 1. If I is out of phase with V, then PF becomes less than 1: more apparent power than actual. Link below explains this further. Small appliances tend to have little reactive behavior so they're simply rated in watts.

Odude at Yahoo! Answers Visit the source

Was this solution helpful to you?

Other answers

Volt/Amps = Resistance (This should not have been included in your question) Volt Amps = (V) x (A) = Apparent power in volt amps (Apparent power) x (Power factor) = True power in watts Power factor = Cosine of the phase angle between voltage and current True power in watts is always equal to or less than apparent power in volt amps. Circuit elements must be designed to handle the extra current required in circuits with a low power factor. The reason for not using only watts or volt amps is because each one defines a quantity in a circuit that is often different from the other and is not related to the other by a fixed coefficient.

Mr. Un-couth

P = EI (Power = Volts x Amps). When the power source is DC (battery, etc.) and the load is pure resistance (electric heater, etc.) with AC or DC the relationship is rather simple. However when the load includes capacitors and reactors (coils of wire) as well as resistors energy can be stored within electromagnetic or electrostatic fields and a power factor may have to be considered to determine power consumption.

Kes

VA and Watts are not the same thing except for DC. In AC theory W=VA*PF (power factor). Power factor is the relationship of current to voltage. When looking at the cyclic voltage and the cyclic current you will see a lag from one to the other, this lag is the power factor. The lag is caused by the inductance or capacitance in the system. Watts is the correct term to use for most products. VA would be used for transformers where you don't know what the load will look like.

protoham

VA is equal to watt. But VA is generally used when equipment is rated, thus for example, a transformer is rated for 50VA. Thus it can handle driving a 50W load.

wummer

volt / amps doesnt equal volts * amps, thats division and multiplication. power is measured in watts so in truth it does equal volt/amps but its universally accepted to just say watts

Anomaly

Related Q & A:

Just Added Q & A:

Find solution

For every problem there is a solution! Proved by Solucija.

  • Got an issue and looking for advice?

  • Ask Solucija to search every corner of the Web for help.

  • Get workable solutions and helpful tips in a moment.

Just ask Solucija about an issue you face and immediately get a list of ready solutions, answers and tips from other Internet users. We always provide the most suitable and complete answer to your question at the top, along with a few good alternatives below.