Laws & Equations Flashcards
Faradays Law:
The magnitude of the EMF Is directly proportional to the rate of change of flux (Applies to generators)
Lenz’s Law:
An inducedelectric currentflows in a direction such that the current opposes the change that induced it
Kirchhoff’s Voltage Law
The sum of the voltage drops around a single closed path equals the sum of the voltage sources
Kirchhoff’s Current Law
At any point in an electrical circuit, the sum of currents flowing towards that point is equal to the sum of currents flowing away from that point
Ohms Law
V=IR
Power Law
P=IV
Left hand rule
Electric motors
Right Hand rule
Electric Generators
EMF Equation
EMF = BLV
B = Magnetic Field L = Length of the object moving V = Speed
Conductance Equation
Conductance (G) = 1/R
Internal resistance equation
Internal resistance = OCV - CCV
-—————
I
Power Equation’s
P = I^2 x R
P = V^2/R
P = V x I
P = Amps x Volts
1 watt =
1 Joule per second
Charge (Q) Equation:
Q = Capacitance x Voltage
Time constant Equation:
5 x R x C
MMF Equation:
MMF = Amps x Turns
Capacitance Equation:
C = KA/d
KA = Dielectric Constant d = Distance plates apart
Field Strength Ident.
H
Flux Density Ident.
B
Field Strength Equation:
H = I x N / L
I = Current N = Number of turns L = Length
Magnetic Flux density (B) Eqution
B = H x permeability
H = Magnetic field Strength
Magnetic Flux equation
Flux = B x A
A = Pole Area B = Flux density
Power in a motor equation:
Torque x 2pi x rev/sec
Torque equation:
Force x radius
