Untitled Flashcards Set
Equations to remember
Quantity | Equation |
Current | Current = charge ÷ time I = Q / t |
Resistance | Resistance = potential difference ÷ current R = V / I |
Voltage | Voltage = current x resistance V = I x R |
Power | Power =current x voltage P = I x V Since Voltage is also current x resistance, Power = current2 x resistance P=I2 x R Power=Voltage2 /Resistance P=V2 /R |
Energy | Energy = power x time E = P x t E = I x V x t E = Q x V |
Cost | Cost of electricity = number of kW h x cost per kW h |
Resistance of a conductor | Resistance= constant ×lengthcross sectional area R=ρLA |
Series and Parallel Circuits information and equations to remember
Current | Voltage | Resistance | |
Series | Same at all points | the total p.d. across the components in a series circuit is equal to the sum of the individual p.d.s across each component | R= R1 + R2 + R3 The sum of the resistance |
parallel | Sum of currents in the branches equals the total current entering or leaving the parallel branch | the p.d. across each branch of a parallel arrangement of components is the p.d. across the whole arrangement |