Flashcards in PHEP 16 Deck (24)
what is capacitance
that property which opposes any change in voltage
what is inductance
that property that opposes any change in current
what are the units of capacitance
what affects capacitance of a capacitor
area of plate, distance between plates, number of plates
what is capacitive reactance
opposition offered by a capacitance to the flow of A-C
current through a capacitor and is expressed in Ohms.
what will happen to the charging current in a capacitor if an alternating voltage is applied
vary as voltage changes
what is the unit used in measuring the size of a capacitor
What is the purpose of of insulation, or an insulator?
To prevent leakage or loss of current.
A dielectric is an insulator that is placed _____________.
Between two conductors
Any two conductors which are separated by an insulator and designed to introduce capacitance within a circuit.
Describe dielectric strength.
IT'S A MEASURE OF THE INSULATING PROPERTY OF THE MATERIAL.
Describe dielectric constant.
IT'S A MEASURE OF AN INSULATORS EFFECTIVENESS.
How do you measure dielectric strength?
It's the VOLTAGE PER CENTIMETER that must be applied to rupture or breakdown an insulator.
What is the constant used to determine a dielectric's effectiveness?
The constant is air, which has a value of 1.
What are the three ways charging current can be increased in a capacitor?
1. Voltage is increased
2. Size of the plates are increased.
3. The plates are moved closer together.
The capacitance in farads is numerically equal to the quantity of electricity in _______.
The intensity of the electrostatic field is proportional to?
the voltage between conductors.
The electrostatic field is proportional to the ________ and the magnetic field is proportional to the ______ carried.
What is considered when constructing parallel-plate capacitors?
The amount of voltage they are to be subjected to.
Capacitance is proportional to?
the cross-sectional area of the dielectric between the plates.
Total capacitance in a parallel circuit is?
Total capacitance in a series circuit is?
Reciprocal of the reciprocal.
What are some capacitor applications?
1. To smooth voltage ripples in D-C circuits.
2. Minimize contact burning in inductive circuits.
3. Supply energy to lightning impulse generators.