science magic triangles?? how to get resistance, power, current...?

It sound's like you're doing simple calcs, where you can assume that current remains proportional to voltage (in practise they end up "out of sync" with AC- but that involves complex numbers/vectors- and you'd know if that's what you have to usu!) Think you need the following, and need to apply/rearrange/combine the following equations V=I*R P=V*I=I*I*R E= P * t = I*I*R*t V= Potential difference across component/supply terminals (Volts) I= Current THROUGH component (Amps) R= Resistance of component (Ohms) P= Power of component (Watts) E= Energy used by component (Joules) The only bit I can remember about charge is how to relate it to capacitance,voltage, and time. http://en.wikipedia.org/wiki/Capacitor#Energy_storage --- For question you've given you have voltage and resistance and need to find the unknown of current. V=220 [V] R= 12 [ohms] calculate current by application of Ohm's Law.... V[Volts]=I[Amps]*R[Ohms] I[Amps]=V[Volts]/R[Ohms] I[Amps= 220 [Volts] /12 [Ohms[ I= 18 + 1/3 Amps --- It doesn't state the power source is AC or DC- I've assumed it's DC. For AC the (simple) answer is the same, but only so long as the 220 V referes to the RMS value of the voltage (as a RMS voltage is a "kind" of average voltage as used for AC)

Voltage is a potential of electrical flow (concentrated charge relative to the rest of the circuit. Current is the flow of electrons. As the current flows, the voltage drops, unless resupplied. Resistance is the resistance o the current flow. More resistance, more voltage drop across the resistor (the resistor burns up electrical potential). Power is rate at which electrical energy is being used. Charge is the quality of an electron which allows it to be pushed through a circuit by applied voltage and its associated electric field. Joules is a measure of energy. This can include electrical energy [e.g., (i^2R)t].

E=IxR P=IxE P=I^R I=E/R 220/12=I