2A AC current
the power factor in a circuit with a resistance of 50 ohm and an impedance of 100 ohm is
0.5
each of 3 = capacitor in series has
1/3 the applied voltage
the current flow on a purely resistive AC circuit if the resistance is 15 ohms and the voltage is 150 volts is
10 amps
If the time for one cycle is 0.1 second, the frequency is _____.
10 herts
how much current will flow in a circuit that is supplied by a 60-Hz, 120-volt source and has a 0.03 henry coil?
10.6 A
in a series LC circuit, the capacitor drops 170 volts and the inductor drops 50 volts. the total voltage is
120 volts
what is the peak voltage in a circuit with an rms voltage of 120VAC?
170 volts
a cuircitu has a peak voltage of 175 volts the average voltgae is
175
what is the voltage across the secondary winding if the primary winding has 120 VAC applied to it, the primary has 200 turns, and the secondary has 300 turns
180 VAC
the step down ratio of a transformer 200 turns in the primary and 100 in the secondary
2-1
the total capacitance of two 5 micro farad capacitors and one 10 micro farad capacitor in parallel is
20 micro farad
in a purely resistive AC circuit where 240V is applied across a 10-ohm resistor, the amperage is
24A
the total capacitance of two 15 micro farad capacitors connected in parallel is
30 micro farad
in a purely resistive circuit containing one 25-ohm resistor powered by 120 AVC, the total current flow is ________ amps.
4.8 amps
what is the frequency of an AC wave form that completed 20 cicles per half second
40 herts
the true power in a 2 amp series rl circuit with 100 ohm resistor is
400 watts
a 30 micro farad capacitor is in parallel with a 15 micro farad capacitor the total capacitance is
45
if resistance and capacitive reactance are equal in a series RC circuit, the phase angle will be
45
a transformer with 10 turns in the primary and two turns in the secondary has a turns ratio of
5
if a 15-and 35- microfarad capacitor are connected in parallel, the total capacitance is __________ microfarads.
50
what is the frequency of a waveform that occurs 500 times in 10 seconds?
50 hz
given frequencies of 60Hz and 50 Hz, which has the shortest period?
60Hz
the total capacitance of two 15 micro farad capacitors in series is
7.5 micro farads
if a transformer has 200 turns the primary 100 turns and the secondary and 150 VAC applied to the primary the voltage across the secondary is going to be
75 VAC
what is the peak value of a waveform that has a peak to peak value of 150 volts?
75 volts
the true power in a circuit with 4A through a 50 ohm resistor is
800W
if the vector diagram of 2 AC wave forms are a right angle then the wave forms are
90 degrees out of phase
Reactive power is always _____.
90° out of phase with true power
which of the following coils is likely to show the lowest inductance
a coil with narrow coils
opening the secondly circuit of a AC transformer under load will cause
a dangerous level of induced voltage
an electric current always produces
a magnetic field
the product of the source voltage and the total current
apparent power
An ------ is often used in fluorescent lighting circuits
autotansformer
the opposition to current flow offered by the capacitance of a circuit is known as
capacitive reactance
A power factor is not an angular measure, but a numerical ratio with a value between 0 and 1, equal to the
cosine of the phase angle
capacitance is measured in
farads
a coil with many turns of wire will induce less voltage than a coil with fewer turns of wire
faulse
the number of cycles an alternating electric current undergoes per second is known as
frequency
according to the power triangle the apparent power is
greater than the true power
a variable capacitor is used to tune a radio to the desired station. at the low end of the AM band (550kHz), will the capacitive reactance (Xc) be higher or lower than it is at the high end of the band (1440kHz)
higher
the total opposition to current flow in an AC circuit is known as
impedance
total opposition to current flow in an AC circuit is cal
impedance
if the phase angle of two sine waves are both 0 degrees then the waves are
in phase
in a purely resistive circuit, the voltage and current will be________
in phase
If the area of the plates of a capacitor is increased, the amount of capacitance _____.
increases
reactance increases with an increase in
inductance
the opposing force that an inductor present to the flow of alternating current is called
inductive reactance
when the current increases in an AC circuit, what role does inductance play?
it reduces the current
if the resistance in a series RL circuit is greater than the inductance, the phase angle will be
less than 45 degrees
a transformer in which the secondary voltage is in phase with the primary voltage is called
like wound
the greatest amount of voltage is induced when the conductor is moving __________to the magnetic field
perpendicular
the two windings of a conventional transformer are known as the
primary and secondary windings
apparent power is the
product of source voltage and total current
in circuit that has both capacitive and resistance the current will lead the voltage by
some angle of 0-90 degrees
which of these items determines the amount of voltage induced in a moving conductor?
speed of conductor, strength of magnetic field rate of movement
One type of nonsinusoidal waveform is the _____.
square wave
which of the statements applies to a parallel RC circuit
the voltage across the branches are in phase
which of the following conditions exist in a circuit of pure infuctance
the voltage and current are 90 degrees out of phase
which of the following conditions exist in a circuit of pure resistance
the voltage and current are in phase
the symbol for phase angle is
theta
the self induced voltage across an inductance is produced by a change in current with respect
to time
a device that uses electromagnetic induction to transfer electrical energy from one circuit to another is a
transformer
An isolation transformer can help prevent electrical shock
true
a power factor can be defined as the ratio of
true power to apparent power
the power factor of a circuit is the ratio of
true power to apparent power
transformer in which the primary and secondary voltages are 180 degrees out of phase are know as
unlike wound tranformers
in an inductor, when the voltage waveform is at 270 degrees, the current waveform will be at________
zero
in inductive AC circuit when the applied voltage is at its maximum negitive vale the current is
zero
when resistance is added to an AC circuit containing a capacitor, current will lead voltage by an angle between
zero and 90 degrees
