FORMULAS in

ELECTRICAL ELEMENTS

CAPACITANCE

where:C = capacitance, Farad (F)V = voltage, Volts (V)Q = charge, Coulomb (C)n = number of parallel-platesA = area of plates, )d = distance between the plates, mε = permittivity of the dielectric

𝑪=𝑸𝑽 =(𝒏−𝟏)𝜺 𝑨

𝒅

ENERGY STORED IN A CAPACITOR

where: = energy stored, Joule (J)C = capacitance, Farad (F)V = voltage, Volts (V)Q = charge, Coulomb (C)

𝑾 𝒄=𝟏𝟐 𝑪𝑽 𝟐=

𝑸𝟐

𝟐𝑪

SERIES CAPACITANCE

where:C = capacitance, Farad (F)

𝑪=𝟏

𝟏𝑪𝟏

+𝟏𝑪𝟐

+….+ 𝟏𝑪𝒏

PARALLEL CAPACITANCE

where:C = capacitance, Farad (F)

𝑪=𝑪𝟏+𝑪𝟐….+𝑪𝒏

INDUCTANCE

where: L = inductance, Henry (H)μ = permeability of the core, (H/m)N = number of turnsA = area of the core, l = mean length of the core, (m)

= N

ENERGY STORED IN AN INDUCTOR

where: = energy stored, Joule (J)L = inductance, Henry (H)I = current, Ampere (A)

𝑾 𝑳=𝟏𝟐 𝑳 𝑰𝟐

MUTUAL INDUCTANCE

where:M = mutual inductance, Henry (H)k = coupling coefficient

𝑴=𝒌√𝑳𝟏𝑳𝟐

SERIES INDUCTORS

where: L = inductance, Henry (H)

𝑳=𝑳𝟏+𝑳𝟐+….+𝑳𝒏

SERIES INDUCTANCE (w/ MUTUAL INDUCTANCE)

where: = total inductance, Henry (H)M = mutual inductance, Henry (H)

Note:+ = when fields are aiding- = when fields are opposing

𝑳𝑻=𝑳𝟏+𝑳𝟐±𝟐𝑴

PARALLEL INDUCTANCES

where:L = inductances, Henry (H)

𝑳=𝟏

𝟏𝑳𝟏

+𝟏𝑳𝟐

+….+ 𝟏𝑳𝒏

PARALLEL INDUCTANCE (w/ MUTUAL INDUCTANCES)

where:L = inductance, Henry (H)M = mutual inductance, Henry (H)

Note:+ = when fields are opposing- = when fields are aiding

𝑳𝑻=𝑳𝟏𝑳𝟐−𝑴 𝟐

𝑳𝟏+𝑳𝟐±𝟐𝑴

where:

𝑳=𝑳𝟏+𝑳𝟐+….+𝑳𝒏