Q: How is DC power calculated in terms of amps and volts?
A: The power (P) in watts can be calculated by multiplying the current (I) in amps by the voltage (V) in volts. The formula is: P(W) = I(A) × V(V).
Q: How is AC single phase power calculated considering power factor, current, and voltage?
A: The power (P) in watts for AC single phase is calculated using the power factor (PF), phase current (I) in amps, and RMS voltage (V) in volts. The formula is: P(W) = PF × I(A) × V(V).
Q: What is the formula for calculating AC three-phase power with line to line voltage?
A: For AC three-phase power with line to line voltage, the formula is: P(W) = √3 × PF × I(A) × VL-L(V), where PF is power factor, I is phase current in amps, and VL-L is line to line RMS voltage in volts.
Q: Can you explain how AC three-phase power is calculated using line to neutral voltage?
A: Certainly. AC three-phase power with line to neutral voltage is calculated using the formula: P(W) = 3 × PF × I(A) × VL-N(V), where PF is power factor, I is phase current in amps, and VL-N is line to neutral RMS voltage in volts.
Q: Are there typical power factor values that should be used in calculations?
A: It's advisable not to use typical power factor values for accurate calculations. Power factors vary depending on the type of device or load. Here are some examples of typical power factors for various devices: resistive load (1), fluorescent lamp (0.95), incandescent lamp (1), induction motor full load (0.85), induction motor no load (0.35), resistive oven (1), synchronous motor (0.9).
Q: Can you provide an alternative formula for converting amps to watts?
A: Certainly. The formula Amps x Volts = Watts can be used for conversion. For instance, if you have 10 amps and 120 volts, you can calculate: 10 Amps x 120 Volts = 1200 Watts.
Q: What do Amps, Volts, and Watts represent in an electrical context?
A: Amps measure the flow of electric current, similar to water flow in a hosepipe. Volts determine the force required for the current to flow, akin to water pressure. Watts represent the energy or power produced when Amps and Volts combine.
Q: What is the relationship between Amps, Volts, and Watts?
A: Watts are the product of Amps and Volts. This relationship can be expressed as Watts = Amps × Volts. Watts indicate the amount of power or energy generated by the combination of current and voltage.
Q: How are AC and DC power systems defined?
A: AC (alternating current) and DC (direct current) refer to the direction of current flow in a circuit. DC flows in a single direction, often seen in batteries. AC changes direction regularly, as seen in household electrical systems, changing direction 50 times per second (50 Hz) in the UK supply.
Q: Can you provide an example of the practical application of AC and DC power?
A: Certainly. A battery-powered torch uses direct current (DC) where current flows in one direction. In contrast, houses, buildings, and mains-connected appliances use alternating current (AC), where current changes direction regularly, typically 50 or 60 times per second.
