Electricity and Magnetism Formulas Flashcards
1
Q
Force between two charges
A
F = k(q1 x q2)/(r^2)
2
Q
Coulomb Constant
A
k = 1/4 x pi x dielectric constant
3
Q
Potential difference
A
V = W/q or V = E/q
4
Q
Current
A
I = Q/t
5
Q
Kirchoff’s first law
A
ΣI = 0 (junction)
6
Q
Kirchoff’s second law
A
ΣV = 0 (loop)
7
Q
Resistance
A
R = V/I
8
Q
Resistivity
A
ρ = RA/L
9
Q
Power
A
P = VI or P = I^2R or P = V^2/R
10
Q
Current in a wire
A
I = nAvq
11
Q
EMF of a cell
A
ε = I(R + r )
12
Q
Force on a charge moving through a magnetic field
A
F = qvBsinθ
13
Q
Force on a current-carrying wire in a magnetic field
A
F =BILsinθ
14
Q
Electric Field Strength
A
E = F/q
15
Q
Potential Gradient
A
E = V/d
