ASSIGNMENT 1
CONDUCTOR AND INDUCTOR
TYPE OF INDUCTOR
TYPE OF CAPACITOR
FIXED
VARIABLE
IRON CORE
FERRITE CORE
AIR CORE
CORE LOSS
DEFINITION OF INDUCTOR
CALLED CHOKE IS ANOTHER PASSIVE TYPE ELECTRICALCOMPONENT DESIGNED TO TAKE ADVANTAGES OF THIS RELATIONSHIP BY PRODUCING A MUCH STRONGER MAGNETIC FIELD THAN ONE THAT WOULD BE PRODUCED BY A SIMPLE COIL
SYMBOL OF INDUCTANCE IS L
UNIT OF INDUCTANCE IS Henry
INDUCTANCE-the propety of an electric circuit by which an electromotive force is induced in it as the result of changing magnetic flux
ELECTROMAGNET-temporary magnet production due to flow of electric current
ELECTROMAGNETIC INDUCTION-production process electric form magnet
FIXED
VARIABLE
UNPOLARISED
POLARIZED
CERAMIC
FILM
MICA
AIR GAP
PAPER
ALUMINIUM
TANTALUM
TRIMMER
DEFINITION OF CAPACITOR
CAPACITOR IS AN ELECTRICAL DEVICE THAT IS USED TO STORED ELECTRICAL ENERGY
UNIT OF CAPACITANCE IS FARAD.THE SYMBOL IS C**
CAPACITANCE IS DEFINED TO BE THE AMOUNT OF CHARGE Q STORED IN BETWEEN THE TWO PLATES FOR A POTENTIAL DIFFERENCE OR VOLTAGE V EXISTING ACROSS THE PLATES
q = charge
C = capacitance
V = voltage
CONSTRUCTION OF INDUCTOR
Inductor stores electrical energy in form of magnetic field.
Inductor is made of coil formed by conductive materials like copper,aluminium etc. The material around and within the coil affects its properties; common types are air-core (only a coil of wire), iron-core, and ferrite core. Iron and ferrite types are more efficient because they conduct the magnetic field much better than air; of the two, ferrite is more efficient because stray electricity cannot flow through it. Ferrite is more expensive but operates at much higher frequencies than iron cores.
CIRCUIT WITH INDUCTIVE LOAD
1. ELECTROMAGNETIC INDUCTION An e.m.f is induced in the conductor as a result of its movement across the
magnetic field͘ This effect is known as ͚electromagnetic induction͛͘ 2. FARADAY'S LAW
An induced e.m.f is setup whenever the magnetic field linking that circuit
changes.The magnitude of the induced e.m.f in any circuit is proportional to the rate of change of the magnetic flux linking the circuit.
THE FACTORS THAT INFLUENCE INDUCTANCE
i) The number of turns of wire (N) ʹ more turns the higher the inductance
ii) The cross-sectional area of the coil of wire (A) ʹ the greater the cross-sectional area
the higher the inductance
iii) The presence of magnetic core - when the coil is wound on an iron core, the same
current sets up a more concentrated magnetic field and the inductance is increased
iv) The way turns are arranged ʹ a short tick coil of wire has a higher inductance than
the along thin one.
CONSTRUCTION OF CONDUCTOR
By applying a voltage to a capacitor and measuring the charge on the plates, the ratio of
the charge Q to the voltage V will give the capacitance value of the capacitor and is therefore
given as: C = Q/V this equation can also be re-arranged to give the more familiar formula for the
quantity of charge on the plates as: Q = C x V.
CAPACITOR EQUIVALENT CIRCUITS
PARALLEL
Total charge,
QT = Q1 + Q2 + Q3
CTE = C1V1 + C2 V2 + C3 V3
Total voltage
ET = e1 = e2 = e3
Total equivalent circuit capacitance
CT = C1 + C2 + C3
It follows that for n parallel connected
capacitors:
CT = C1 + C2 + C3 н͙͙н Cn
SERIES-PARALLEL Total equivalent circuit capacitance Ct=C1/(C2+C3)
SERIES
Total voltage
VT = e1 + e2 + e3
Where CT is the total equivalent circuit
capacitance
1/CT=1/C1+1/C2+1/C3+....
ELEMENT RELATED TO CAPACITANCE
a.Electric field:
b. Line of electric force: .
c. Electric flux:
d. Electric flux density (D):
e. Electric field strength:
f. Dielectric: .
g. Absolute permittivity (ɸ):
FACTOR EFFECTING CAPACITANCE
a.Capacitance between two plates proportional to the surface area
b. Capacitance between two plates inversely proportional to the thickness of
dielectric
c. Increasing the dielectric constant of the material between the plates
CHARGING AND DISCHARGING
INDUCTANCE EQUIVALENTS CIRCUIT
PARALLEL
Total voltage,
ET = e1 = e2
Total current,
IT = I1 + I2
Total inductance
1/LT=1/L1+1/L2
SERIES-PARALLEL
Total current,
IT = I1 +I2
Total inductance,
LT=L1+(L2L3/(L2+L3))
SERIES
Total voltage,
ET = e1 + e2
Total inductance,
LT = L1 + L2
Current, I = IL1 = IL2
RISE AND DECAY CURRENT