Electricity formulas Flashcards
1
Q
rules of attraction
A
- like forces repel
- unlike forces attract
2
Q
formula connecting p.d., energy and charge
A
p.d. = energy/charge V = E/Q
3
Q
unit of p.d. (V)
A
volts (V)
4
Q
unit of energy (E)
A
joules (J)
5
Q
unit of charge (Q)
A
coulombs (C)
6
Q
1V =
A
1 joule per coulomb
7
Q
formula connecting charge, current and time
A
charge = current x time
Q=It
8
Q
unit of charge (Q)
A
coulombs (C)
9
Q
unit of current (I)
A
amps (A)
10
Q
unit of time (t)
A
seconds (s)
11
Q
Ohm’s law Ω
A
resistance = p.d. / current R = V/I
12
Q
convert A to mA
A
x1000
13
Q
formula for energy input to a component
A
energy = p.d. x current x time E= VIt
14
Q
formula relating power, energy and time
A
power= energy/time
15
Q
formula relating power, p.d. and current
A
power = p.d. x current P= VI
