Basic Electricity Flashcards
(122 cards)
The working voltage of a capacitor in an AC circuit should be…
at least 50 percent greater than the highest applied voltage.
The term that describes the combined resistive forces in an AC circuit is…
impedance.
What is the opposition to the flow of AC produced by an electromagnetic field (EMF) with generated back voltage called?
Inductive reactance.
Electrostatic fields are also known as…
dielectric fields.
The basis for transformer operation in the use of alternating current is mutual.
inductance.
The opposition offered by a coil to the flow of alternating current (ignoring resistance) is called…
inductive reactance.
What factors strengthen a coil inductor?
Adding coils close together.
An increase in which of the following factors will cause an increase in the inductive reactance of a circuit?
Inductance and frequency.
When different rated capacitors are connected in series in a circuit, the total capacitance is…
less than the capacitance of the lowest rated capacitor.
Capacitors are sometimes used in DC circuits to…
smooth out slight pulsations in current/voltage.
In an AC circuit, the effective voltage is…
less than the maximum instantaneous voltage.
The amount of electricity a capacitor can store is directly proportional to the…
plate area and inversely proportional to the distance between the plates.
What is the total capacitance of a certain circuit containing three capacitors with capacitances of 0.02 microfarad, 0.05 microfarad, and 0.10 microfarad, respectively?
0.0125 microfarad.
What is the total capacitance of a circuit containing three capacitors in parallel with capacitances of 0.02 microfarad, 0.05 microfarad, and 0.10 microfarad, respectively?
0.170 microfarad.
Converts farad to microfarads by…
multiplying farads by 10 to the power of 6.
Convert farads to picofarads by…
multiplying farads by 10 to the power of 12.
Unless otherwise specified, any values given for current or voltage in an AC circuit are assumed to be…
effective values.
When different rated capacitors are connected in parallel in a circuit, the total capacitance is (Note: Ct = C1 + C2 + C3…)…
equal to the sum of all the capacitances.
When inductors are connected in series in a circuit, the total inductance (where the magnetic fields of each inductor do not affect the others) is… (Note: Lt = L1 + L2 + L3…)
equal to the sum of the individual inductances.
When more than two inductors of different inductances are connected in parallel in a circuit, the total inductance is…
less than the inductance of the lowest rated inductor.
What is the total capacitance of a certain circuit containing three capacitors with capacitances of 0.25 microfarad, 0.03 microfarad, and 0.12 microfarad, respectively? (Note: Ct = C1 + C2 + C3)
0.4 microfarad.
Which requires the most electrical power during operation? (Note: 1 horsepower = 746 watts)
Two lights requiring 3 amperes each in a 24-volt parallel system.
450 watts.
A 12-volt electric motor has 1000 watts input and 1 horsepower output. Maintaining the same efficiency, how much input power will a 24-volt , 1-horsepower electric motor require? (Note: 1 horsepower = 746 watts)
1000 watts.