Description : The plate voltage of a tube will vary 126 volts when a 3-volt ac signal is applied to the control grid. What is the gain of this tube?
Last Answer : 42.
Description : A tube has a transconductance of 800 mhos and a load resistor of 50 kohms. When control grid voltage varies by 6 volts, the plate voltage will vary by what amount?
Last Answer : 240 volts.
Description : How does transit time affect the relationship of the grid voltage and the plate current at high frequencies?
Last Answer : Transit time causes the grid voltage and plate current to be out of phase
Description : What effect does the shielding of the screen grid by the control grid have on plate current in beam-forming tetrodes?
Last Answer : By increasing the number of electrons that reach the plate, plate current is increased.
Description : What is the purpose of either 'setpoint module' (6000F090/030) shown in the illustration? EL-0094 A. Program the 'signal conditioner' as to how to vary its input. B. Supply 0 - 10 volts to ... . Obtain an input from the 'signal conditioner' and, if outside set limits, signals the 'annunciator'.
Last Answer : Answer: D
Description : A large negative voltage is applied to the plate of a diode, and a largewhat tube parameter has been exceeded?
Last Answer : Peak Inverse Voltage (PIV).
Description : Why does the grid have a greater effect than the plate on electron flo
Last Answer : Because it is closer to the cathode.
Description : The most practical way to control the voltage output of an AC generator is to vary the _____________. A. number of windings B. speed of the rotating field C. strength of the rotating magnetic field D. power factor of the load
Last Answer : Answer: C
Description : Automatic voltage regulators provided on switchboards function to _____________. A. regulate the AC load on the generator B. protect the switchboard from high voltage C. govern prime mover speed to control voltage D. vary the field excitation to the generators
Description : How much must the fpa plate current vary to produce 100- percent modulation in a plate modulator?
Last Answer : Between 0 and nearly two times its unmodulated value.
Description : An ac voltage is applied across a diode. The tube will conduct when
Last Answer : Positive.
Description : Why does using ac vice dc bias voltage result in a stronger output signal?
Last Answer : Because an ac bias voltage of the proper frequency and level places the input signal away from both steps in the magnetism curve. The result is two undistorted output signals that are combined into one strong output.
Description : What are three advantages of adding an ac bias voltage to the input signal instead of adding a fixed dc bias voltage?
Last Answer : a. Reproduces a stronger output signal. b. Greatly improves the SNR. c. Greatly reduces the natural tape hiss.
Description : Why does adding dc vice ac bias voltage to the input signal result in a poor signal-to-noise ratio (SNR)?
Last Answer : With dc bias, the SNR is poor because only a small portion of the magnetism curve is straight enough to use, thus the output signal is weak compared with the natural tape hiss.
Description : What is the approximate voltage per cell produced by the nickel-iron (Edison) battery? A. 0.85 volts B. 1.35 volts C. 2.20 volts D. 6.05 volts
Last Answer : Answer: B
Description : When the circuit shown in the illustration is operating correctly, the voltage at the reference electrode will be kept in the optimum range of ____________. EL-0090 A. 0.01 - 0.05 volt B. 0.80 - 0.85 volt C. 35 - 60 volts D. 100 - 115 volts
Description : A positive damper clamps which extremity of the output signal to 0 volts?
Last Answer : Most negative.
Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A
Last Answer : D. 2.0 A
Description : When a wide band of frequencies is transmitted simultaneously, each frequency will vary in the amount of fading. What is this variable fading called?
Last Answer : Selective fading.
Description : The most practical method of controlling the RPM of a step-speed AC motor is to _____________. A. change input voltage B. vary the number of poles C. vary power factor D. change the number of brushes
Description : Regarding an AC generator connected to the main electrical bus; as the electric load and power factor vary, a corresponding change is reflected in the generator armature reaction. These changes in ... . governor speed droop setting B. voltage regulator C. balance coil D. phase-balance relay
Description : What would be the output of a negative clamper with a bias potential of −5 volts and an input voltage swing from +50 to −50 volts?
Last Answer : -5 volts.
Description : What is the average voltage (Eavg) Output of a full-wave rectifier with an output of 100 volts peak?
Last Answer : 63.7 volts.
Description : If the output of a half-wave rectifier is 50-volts peak, what is the average voltage
Last Answer : 15.9 volts.
Description : What is the average voltage (Eavg) output of a full-wave rectifier that has an output of 100 volts peak?
Last Answer : 63.6 volts.
Description : If the source voltage for the voltage divider in question 50 supplies 150 volts, what is the total current through the voltage divider?
Last Answer : 495 mA.
Description : A circuit has a source voltage of 100 volts and two 50-ohm resistors connected in series. If the reference point for this circuit is placed between the two resistors, what would be the voltage at the reference point?
Last Answer : 50 volts.
Description : Using the graph in figure 3-7, what is the approximate value of current when the voltage is 12.5 volts?
Last Answer : 1.25 amperes.
Description : a. Define the term "working voltage" of a capacitor. b. What should be the working voltage of a capacitor in a circuit that is operating at 600 volts?
Last Answer : a. It is the maximum voltage the capacitor can work without risk of damage. b. 900 volts.
Description : Once ionization has occurred in a thyratron, what control does the control grid have over the tube’s operation?
Last Answer : None.
Description : Why the control grid of a triode amplifier is negatively biased?
Last Answer : To prevent them from drawing grid current.
Description : When is a control-grid modulator used?
Last Answer : In cases when the use of a minimum of af modulator power is desired.
Description : If the supply voltage is 220 volts 60 Hz, what is the operating voltage of the motor controller circuitry illustrated? EL-0011 A. 110 volts DC B. 110 volts AC C. 220 volts DC D. 220 volts AC
Description : In the output of an ac error detector, what indicates the (a) direction and (b) amount of control necessary for correspondence?
Last Answer : (a) Phase. (b) Amplitude.
Description : A triac thyristor functions as a control device and is basically ________________. A. two NPN transistors in parallel with a common base lead B. a diode in series with a temperature sensitive capacitor C. two ... -back SCR's with a common gate lead D. a triode tube with an extra heavy grid element
Description : A small object is 2 cm below the concave meniscus of water in a test tube . The radius of the meniscus is 5mm and `mu` for water is `4//3`. Find the n
Last Answer : A small object is 2 cm below the concave meniscus of water in a test tube . The radius of the ... /3`. Find the nature and position of the image.
Description : An electric current of `2.0 mu A` exists in a discharge tube. How much charge flows across a cross-section of the tube in 5 minutes ?
Last Answer : An electric current of `2.0 mu A` exists in a discharge tube. How much charge flows across a cross-section of the tube in 5 minutes ?
Description : One method of troubleshooting digital circuits in a console is to ___________. A. supply alternate logic levels at the input(s) and test for change of state conditions at the output B. ground all ... output D. vary each input smoothly from 0-10 volts and test for similar variance at the output
Last Answer : Answer: A
Description : rid-leak biasing in effect rectifies the input ac signal. What feature
Last Answer : Unequal charge and discharge paths of the coupling capacitor Cc.
Description : Does a rectifier tube conduct on the positive or negative alternation of the input signal?
Description : A three-phase alternator is operating at 450 volts, 250 amps at 0.6 power factor. If the power factor increases to 0.8, the kw load potential will increase by _____________. A. 38.525 kw B. 116.91 kw C. 155.88 kw D. 194.85 kw
Description : A three-phase alternator operates at 450 volts with a power factor of 0.8. If the ammeter indicates 250 amperes, what should be the KW meter reading? A. 90.00 KW B. 127.27 KW C. 155.70 KW D. 194.85 KW
Description : Which of the following precautions should be taken when troubleshooting various power circuits using a common solenoid-type mechanical voltage tester (wiggins)? A. Never use this tester on circuits greater ... voltage expected in the circuit in order to prevent damage from an off-scale reading.
Description : What is the term used to identify the amount of field strength required to cause the electrons to just miss the plate and return to the filament in a circular orbit?
Last Answer : The critical value of field strength
Description : Cathode rays in a discharge tube are made up of electrons emitted from the plate that is connected to the negative terminal of the DC voltage source.
Last Answer : Cathode rays in a discharge tube are made up of electrons emitted from the plate that is connected to the negative terminal of the DC voltage source.
Description : Which of the listed components does line 'C' represent for the transistor illustrated? EL-0068 A. Grid B. Plate C. Emitter D. Collector
Description : What are the three elements of a bipolar transistor? Are they the: w) grid, plate, cathode x) suppressor, deflector, target y) energizer, controller, terminus z) emitter, base, collector
Last Answer : ANSWER: Z -- EMITTER, BASE, COLLECTOR
Description : A printed page is kept pressed by a glass cube `(mu = 1.6)` of edge 6.0cm. By what amount will the printed letters appear to be shifted when viewed fr
Last Answer : A printed page is kept pressed by a glass cube `(mu = 1.6)` of edge 6.0cm. By what ... letters appear to be shifted when viewed from the top ?
Description : If an ac voltmeter is connected between the S2 and S3 windings on a TX, at what two rotor positions should the voltmeter read maximum voltage?
Last Answer : . 150º and 330º
Description : What component causes a generator to produce dc voltage rather than ac voltage at its output terminals?
Last Answer : A commutator