Physics · Grades 8–12
Electricity & circuits · Formula reference
Formula reference
Rule and assumptions
Charge transferred by current
Current is a rate of charge transfer; use seconds, not minutes, here.
Q = It
Current in an ohmic resistor
Assume an ohmic resistor at constant temperature; circuit values are theoretical.
I = V/R
Power in a series resistor network
Ideal source and wires; resistors are ohmic and connected in series.
P = V²/(R₁ + R₂)
Total current in parallel branches
Each parallel branch has the same potential difference; branch currents add.
I = V/R₁ + V/R₂
Energy in kilowatt-hours
A kilowatt-hour is energy, not power.
E(kWh) = P(W) × t(h)/1000
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.