Basic Electricity Flashcards
The working voltage of a capacitor in an AC circuit should be:
A. Equal to the highest applied voltage.
B. At least 20 percent greater than the highest applied voltage.
C. At least 50 percent greater than the highest applied voltage.
C. At least 50 percent greater than the highest applied voltage.
The term that describes the combined resistive forces in an AC circuit is:
A. Resistance.
B. Reactance.
C. Impedance.
C. Impedance.
What is the opposition to the flow of AC produced by an electromagnetic field (EMF) with generated back voltage called?
A. Inductive reactance.
B. Capacitive reactance.
C. Mutual inductance.
A. Inductive reactance.
Electrostatic fields are also known as:
A. Dielectric fields.
B. Electrostatic fields.
C. Static fields.
A. Dielectric fields.
The basis for transformer operation in the use of alternating current is mutual:
A. Inductance.
B. Capacitance.
C. Reactance.
A. Inductance.
The opposition offered by a coil to the flow of alternating current (ignoring resistance) is called:
A. Impedance.
B. Reluctance.
C. Inductive reactance.
C. Inductive reactance.
What factors strengthen a coil inductor?
A. Limiting and separating the coils.
B. Adding and separating the coils.
C. Adding coils close together.
C. Adding coils close together.
An increase in which of the following factors will cause an increase in the inductive reactance of a circuit?
A. Inductance and frequency.
B. Resistance and voltage.
C. Resistance and capacitive reactance.
A. Inductance and frequency.
(Refer to figure 1.) when different rated capacitors are connected in series in a circuit, the total capacitance is:
A. Less than the capacitance of the lowest rated capacitor.
B. Greater than the capacitance of the highest rated capacitor.
C. Equal to the sum of all the capacitances.
A. Less than the capacitance of the lowest rated capacitor.
Capacitors are sometimes used in DC circuits to:
A. Counteract inductive reactance at specific locations.
B. Smooth out slight pulsations in current/voltage.
C. Assist in stepping voltage and current up and/or down.
B. Smooth out slight pulsations in current/voltage.
In an AC circuit, the effective voltage is:
A. Equal to the maximum instantaneous voltage.
B. Greater than the maximum instantaneous voltage.
C. Less than the maximum instantaneous voltage.
C. Less than the maximum instantaneous voltage.
The amount of electricity a capacitor can store is directly proportional to the:
A. Distance between the plates and inversely proportional to the plate area.
B. Plate area and is not affected by the distance between the plates.
C. Plate area and inversely proportional to the distance between the plates.
C. Plate area and inversely proportional to the distance between the plates.
(Refer to figure 2) What is the total capacitance of a certain circuit containing three capacitors with capacitances of .02 microfarad, .05 microfarad, and .10 microfarad, respectively?
A. .170 uF.
B. 0.125 pF.
C. .0125 uF.
C. .0125 uF.
What is the total capacitance of a certain circuit containing three capacitors in parallel with capacitances of .02 microfarad, .05 microfarad, and .10 microfarad, respectively?
A. .170 uF.
B. 0.125 uF.
C. .0125 uF.
A. .170 uF.
Convert farads to microfarads by:
A. Multiplying farads by 10 to the power of 6.
B. Multiplying picfarads by 10 to the power of 6.
C. Multiplying microfarads by 10 to the power 6.
A. Multiplying farads by 10 to the power of 6.
Convert farads to picofarads by:
A. Multiplying farads by 10 to the power of 12.
B. Multiplying picofarads by 10 to the power of -12.
C. Multiplying microfarads by 10 to the power of 12.
A. 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:
A. Instantaneous values.
B. Effective values.
C. Maximum values.
B. Effective values.
When different rated capacitors are connected i parallel in a circuit, the total capacitance is:
A. Less than the capacitance of the lowest rated capacitor.
B. Equal to the capacitance of the highest rated capacitor.
C. Equal to the sum of all the capacitances.
C. Equal to the sum of all the capacitances.