SUB-ELEMENT B Flashcards
What value of series resistor would be needed to obtain a full scale deflection on a 50 microamp DC meter with an applied voltage of 200 volts DC?
A. 4 megohms.
B. 2 megohms.
C. 400 kilohms.
D. 200 kilohms.
A
Which of the following Ohms Law formulas is incorrect?
A. I = E / R
B. I = R / E
C. E = I x R
D. R = E / I
B
If a current of 2 amperes flows through a 50-ohm resistor, what is the voltage across the resistor?
A. 25 volts.
B. 52 volts.
C. 200 volts.
D. 100 volts.
D
If a 100-ohm resistor is connected across 200 volts, what is the current through the resistor?
A. 2 amperes.
B. 1 ampere.
C. 300 amperes.
D. 20,000 amperes.
A
If a current of 3 amperes flows through a resistor connected to 90 volts, what is the resistance?
A. 3 ohms.
B. 30 ohms.
C. 93 ohms.
D. 270 ohms.
B
A relay coil has 500 ohms resistance, and operates on 125 mA. What value of resistance should be connected in series with it to operate from 110 V DC?
A. 150 ohms.
B. 220 ohms.
C. 380 ohms.
D. 470 ohms.
C
What is the peak-to-peak RF voltage on the 50 ohm output of a 100 watt transmitter?
A. 70 volts. C. 140 volts.
B. 100 volts. D. 200 volts.
D
What is the maximum DC or RMS voltage that may be connected across a 20 watt, 2000 ohm resistor?
A. 10 volts.
B. 100 volts.
C. 200 volts.
D. 10,000 volts.
C
A 500-ohm, 2-watt resistor and a 1500-ohm, 1-watt resistor are connected in parallel. What is the maximum voltage that can be applied across the parallel circuit without exceeding wattage ratings?
A. 22.4 volts. C. 38.7 volts.
B. 31.6 volts. D. 875 volts.
B
In Figure 3B1, what is the voltage drop across R1?
A. 9 volts. C. 5 volts.
B. 7 volts. D. 3 volts.
C
In Figure 3B2, what is the voltage drop across R1?
A. 1.2 volts. C. 3.7 volts.
B. 2.4 volts. D. 9 volts.
D
What is the maximum rated current-carrying capacity of a resistor marked “2000 ohms, 200 watts”?
A. 0.316 amps. C. 10 amps.
B. 3.16 amps. D. 100 amps.
A
What is the most the actual transmit frequency could differ from a reading of 462,100,000 Hertz on a frequency counter with a time base accuracy of ± 0.1 ppm?
A. 46.21 Hz.
B. 0.1 MHz.
C. 462.1 Hz.
D. 0.2 MHz.
A
The second harmonic of a 380 kHz frequency is:
A. 2 MHz.
B. 760 kHz.
C. 190 kHz.
D. 144.4 GHz.
B
What is the second harmonic of SSB frequency 4146 kHz?
A. 8292 kHz.
B. 4.146 MHz.
C. 2073 kHz.
D. 12438 kHz.
A
What 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?
A. 165.2 Hz.
B. 15.652 kHz.
C. 156.52 Hz.
D. 1.4652 MHz.
C
What 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 +/- 10 ppm?
A. 146.52 Hz.
B. 1565.20 Hz.
C. 10 Hz.
D. 156.52 kHz.
B
What is the most the actual transmitter frequency could differ from a reading of 462,100,000 hertz on a frequency counter with a time base accuracy of ± 1.0 ppm?
A. 46.21 MHz.
B. 10 Hz.
C. 1.0 MHz.
D. 462.1 Hz.
D
At pi/3 radians, what is the amplitude of a sine-wave having a peak value of 5 volts?
A. -4.3 volts. C. +2.5 volts.
B. -2.5 volts. D. +4.3 volts.
D
At 150 degrees, what is the amplitude of a sine-wave having a peak value of 5 volts?
A. -4.3 volts. C. +2.5 volts.
B. -2.5 volts. D. +4.3 volts.
C
At 240 degrees, what is the amplitude of a sine-wave having a peak value of 5 volts?
A. -4.3 volts. C. +2.5 volts.
B. -2.5 volts. D. +4.3 volts.
A
What is the equivalent to the root-mean-square value of an AC voltage?
A. AC voltage is the square root of the average AC value.
B. The DC voltage causing the same heating in a given resistor at the peak AC voltage.
C. The AC voltage found by taking the square of the average value of the peak AC voltage.
D. The DC voltage causing the same heating in a given resistor as the RMS AC voltage of the same value.
D
What is the RMS value of a 340-volt peak-to-peak pure sine wave?
A. 170 volts AC. C. 120 volts AC.
B. 240 volts AC. D. 350 volts AC.
C
Determine the phase relationship between the two signals shown in Figure 3B3.
A. A is lagging B by 90 degrees.
B. B is lagging A by 90 degrees.
C. A is leading B by 180 degrees.
D. B is leading A by 90 degrees.
B