GROL Licensing Flashcards
(100 cards)
What is the term for the out of phase power associated with inductors and capacitors?
Reactive Power
The opposition to the creation of magnetic lines of force in a magnetic circuit is known as:
Reluctance
What is the relative dielectric constant for air?
1
How would you calculate the total capacitance of three capacitors in parallel?
Ct = C1 + C2 + C3
How does the input impedance of a field-effect transistor compare with that of a bipolar transistor?
An FET has high input impedance; a bipolar transistor has low input impedance.
By what factor must the voltage measured in an AC circuit, as indicated on the scale of an AC voltmeter, be multiplied to obtain the average voltage value?
0.9
What is a sine wave?
A wave whose amplitude at any given instant can be represented by the projection of a point on a wheel rotating at a uniform speed.
Halving the cross-sectional area of a conductor will:
Double the resistance.
Which of the following Ohms Law formulas is incorrect?
I = R/E
What is the maximum DC or RMS voltage that may be connected across a 20-watt, 2000-ohm resistor?
200 volts
Wat is the most the actual transmitter frequency could differ from a reading of 156,520,000 hertz on a frequency counter with a time base accuracy of +- 1.0 ppm?
156.52 Hz
What is the RMS value of a 340-volt peak-to-peak pure sine wave?
120 volts AC
746 watts, corresponding to the lifting of 550 pounds at the rate of one-foot-per-second, is the equivalent of how much horsepower?
One Horsepower
What is the meaning of the term “time constant of an RC circuit”? The time required to charge the capacitor in the circuit to:
23.7% of the supply voltage.
What is the time constant of a circuit having two 220-microfarad capacitors and two 1-megohm resistors all in series?
220 seconds
In rectangular coordinates, what is the impedance of a network composed of a 1.0-millihenry inductor in series with a 200-ohm resistor, at 30 kHz?
200 + j188
What is the impedance of a network composed of a 100-picofarad capacitor in parallel with a 4000-ohm resistor, at 500 KHz? Specify your answer in polar coordinates
2490 ohms, / -51.5 degrees
Given a power supply with a full load voltage of 200 volts and a regulation of 25%, what is the no load voltage?
250 volts
What is the photoconductive effect?
The increased conductivity of an illuminated semiconductor junction
In figure 3C5 , what capacitor (labeled 1 through 4) is being used as a bypass capacitor?
3
What is the ratio of he output frequency to the input frequency of a single-phase full-wave rectifier?
2:1
A switching electronic voltage regulator:
Switches the control device on or off, with the duty cycle proportional to the line or load conditions
What is the transistor called that is fabricated as two complementary SCRs in parallel with a common gate terminal?
TRIAC
What type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies?
Varactor diode