Copyrighted material - Taylor & Francis
Copyrighted material - Taylor & Francis
Magnetic circuits
General Charge Q = It Force F = ma
B=
NI Fm = NI H = A l
W t
S=
mmf l = μ0 μr A
Work W = Fs Power P = Energy W = Pt
Ohm’s law V = IR or I = Conductance G =
V V or R = R I
B = μ0 μr H
Electromagnetism F = BIlsin θ F = Qv B
1 R
V2 ρl Resistance R = R a Resistance at θ ◦ C, Rθ = R0 (1 +α0 θ )
Power P = VI = I 2R =
Terminal p.d. of source, V = E − Ir Series circuit R = R1 + R2 + R3 + · · · Parallel network
Part 1
Main formulae for Part 1 Basic electrical and electronic principles
1 1 1 1 + + + ··· = R R1 R2 R3
Electromagnetic induction E = Blv sin θ E = −N
d dI = −L dt dt
1 W = LI2 2 L=
N N2 = I S
E 2 = −M
dI1 dt
M=
N1 N2 S
Capacitors and capacitance V Q Q E= C= Q = It D = d V A D = ε0 εr E ε0 εr A(n − 1) C= d Capacitors in parallel C = C1 + C2 + C3 + · · · 1 1 1 1 Capacitors in series = + + + ··· C C1 C2 C3 1 W = CV2 2
Measurements Shunt Rs =
Ia r a V − I ra Multiplier R M = Is I
Power in decibels =10 log
I2 V2 P2 = 20 log = 20 log P1 I1 V1
R2 R3 R1 l2 Potentiometer E 2 = E 1 l1 Wheatstone bridge Rx =
These formulae are available for download at the website: www.routledge.com/cw/bird
Magnetic circuits
General Charge Q = It Force F = ma
B=
NI Fm = NI H = A l
W t
S=
mmf l = μ0 μr A
Work W = Fs Power P = Energy W = Pt
Ohm’s law V = IR or I = Conductance G =
V V or R = R I
B = μ0 μr H
Electromagnetism F = BIlsin θ F = Qv B
1 R
V2 ρl Resistance R = R a Resistance at θ ◦ C, Rθ = R0 (1 +α0 θ )
Power P = VI = I 2R =
Terminal p.d. of source, V = E − Ir Series circuit R = R1 + R2 + R3 + · · · Parallel network
Part 1
Main formulae for Part 1 Basic electrical and electronic principles
1 1 1 1 + + + ··· = R R1 R2 R3
Electromagnetic induction E = Blv sin θ E = −N
d dI = −L dt dt
1 W = LI2 2 L=
N N2 = I S
E 2 = −M
dI1 dt
M=
N1 N2 S
Capacitors and capacitance V Q Q E= C= Q = It D = d V A D = ε0 εr E ε0 εr A(n − 1) C= d Capacitors in parallel C = C1 + C2 + C3 + · · · 1 1 1 1 Capacitors in series = + + + ··· C C1 C2 C3 1 W = CV2 2
Measurements Shunt Rs =
Ia r a V − I ra Multiplier R M = Is I
Power in decibels =10 log
I2 V2 P2 = 20 log = 20 log P1 I1 V1
R2 R3 R1 l2 Potentiometer E 2 = E 1 l1 Wheatstone bridge Rx =
These formulae are available for download at the website: www.routledge.com/cw/bird
