Science · Grades 9–10
Electricity & circuits · Formula sheet
Rules, conditions and small examples in one printable reference.
Remember this
Ohm’s law
Applies to an ohmic component under constant physical conditions.
V = IR
6 × 42 = 252
Electrical power
For a steady DC circuit, multiply voltage by current.
P = VI (steady DC)
9 × 2 = 18
Resistors in series
The same current passes through ideal series components.
R_total = R₁ + R₂ + …
4 + 63 + 11 = 78
Two parallel resistors
The equivalent resistance is less than either positive branch resistance.
R = R₁R₂/(R₁ + R₂)
12 × 36 / (12 + 36) = 9
Charge transferred
This relation uses constant current in amperes and time in seconds.
Q = It
6 × 88 = 528
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.