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 : 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 : In the illustration, the diode between terminals 16 and 17 is to _________. EL-0046 A. act as a short circuit for the sensing coil when CEMF is applied B. insure that the voltage across the coil does not exceed 9 volts C. improve response time D. act as a filter to prevent hunting
Last Answer : Answer: A
Description : Before a diode will conduct, the cathode must be what polarity relative
Last Answer : Negative.
Description : In a semiconductor diode, p-side is earthed and to n-side is applied a potential of -2 volt; the diode shall (a) Conduct (b) Not conduct (c) Conduct partially (d) Break down
Last Answer : a) Conduct
Description : If the mu of a tube is 85 and the signal at the control grid is 4 volts ac, the plate voltage will vary by what amount?
Last Answer : 340 volts.
Description : In an AC circuit, the voltage across R, L and C are 30 V, 60 V and 20 V respectively. The applied voltage is (A) 70 V (B) 50 V (C) 60 V (D) 100 V
Last Answer : In an AC circuit, the voltage across R, L and C are 30 V, 60 V and 20 V respectively. The applied voltage is 50 V
Description : Does a rectifier tube conduct on the positive or negative alternation of the input signal?
Last Answer : Positive.
Description : What causes dc bias energy to be absorbed by avalanche electrons and given up to the microwave field applied to an avalanche transit-time diode?
Last Answer : The negative-resistance property.
Description : What is the capacitive reactance across a point-contact diode as compared to a normal junction diode?
Last Answer : Lower.
Description : How does the current-diode detector differ from the voltage-diode detector?
Last Answer : The current-diode detector is in parallel with the input and load.
Description : In the illustration, the diode between terminals 16 and 17 is to _________. EL-0046 A. insure that the voltage across the governor coil (EG-3P) never exceeds .6 VDC B. compensate for the ... heating up C. protect the electronic governor from counter EMF D. act as a filter to prevent hunting
Last Answer : Answer: C
Description : You have installed a Zener diode in parallel with a load. While measuring the voltage across the Zener diode it is found that it does not change as the current through the load increases. This means that the ... is working as it should B. is shorted C. is open D. does not regulate as it should
Description : A circuit which develops voltage across the horizontal deflection plates is known as a) Time base generator b) Electron gun c) Thermionic diode d) Zener diode
Last Answer : a) Time base generator
Description : With a 12 V supply, a silicon diode, and a 370 - ohm resistor in series, what voltage will be dropped across the diode? a) 0.3V b) 0.7V c) 0.9V d) 1.4V
Last Answer : 0.7V
Description : The electron beam in a CRT is made to sweep from left to right across the screen. What tube element causes this sweeping motion?
Last Answer : The horizontal-deflection plate.
Description : Ionisation potential applied across the electrodes of electrostatic tar precipitator is around (A) 230 V AC (B) 60 KV AC (C) 230 V DC (D) 60 KV DC
Last Answer : (D) 60 KV DC
Description : What is the relationship between the polarity of the voltage applied to the PNP transistor and that applied to the NPN transistor?
Last Answer : The polarity of voltage applied to the PNP transistor is opposite of that applied to the NPN
Description : To properly bias an NPN transistor, what polarity voltage is applied to the collector, and what is its relationship to the base voltage?
Last Answer : Positive, more positive.
Description : . In a common anode, seven-segment LED display, an individual LED will light if a negative voltage is applied to what element?
Last Answer : The cathode.
Description : According to Ohm’s law, what happens to circuit current if the applied voltage (a) increases, (b) decreases?
Last Answer : (a) Current increases (b) Current decreases
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 : 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 component causes a generator to produce dc voltage rather than ac voltage at its output terminals?
Last Answer : A commutator
Description : The frequency response of test equipment refers to what aspect of ac voltage measurements?
Last Answer : the range of frequencies that can accurately be measured.
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 : When an AC voltage, of variable frequency is applied to series L-C-R circuit, the current in the cirucit is the same at 4kHz. The current in the cirui
Last Answer : When an AC voltage, of variable frequency is applied to series L-C-R circuit, the current in the cirucit ... is maximum at (x)kHz. Find the value of x
Description : Three factors responsible for the change in voltage as load is applied to an AC generator are: 1) the drop in resistance in the armature circuit, 2) the change in flux, and 3) the ____________. A. armature winding speed B. inductance load drop C. coil pitch factor D. armature reactance voltage drop
Last Answer : Answer: D
Description : The electrical supply applied to the anodes shown in the illustration is _____________. EL-0090 A. low voltage, high current DC B. low voltage, high current AC C. high voltage, low current DC D. high voltage, low current AC
Description : Turn ratio of a transformer is 5. If 220 V AC is applied to its primary coil, voltage in the secondary coil will be: a. 44V b. 4.4 V c. 220V d. 1100V
Last Answer : c. 220V
Description : An AC supply of 230 V is applied to half wave rectifier circuit. A transformer turns ratio is 20 : 1. Find i) Output DC voltage (ii) Peak Inverse Voltage (PIV)
Last Answer : Solution:
Description : A high voltage applied to a gas discharge tube containing neon gas at very low pressure causes a current to flow through the tube. Which one of the following are the particles that flow towards the ... Are they w) electrons x) protons y) negatively charged neon ions z) positively charged neon ions
Last Answer : ANSWER: Z -- POSITIVELY CHARGED NEON IONS
Description : What causes a voltage to be developed across the secondary winding of a transformer?
Last Answer : The magnetic lines generated by the current in the primary cut
Description : the voltage drop across RS and R1 determines the amount of base-emitter ____ for Q1.
Last Answer : Bias.
Description : how is (a) the current through R2 and (b) the voltage drop across R2 computed?
Last Answer : (a) By adding the bleeder current (IR1) and the current through load 1(b) By subtracting the voltage of load 1 from the voltage of load 2.
Description : If the current was increased to 4 amps, what would be the voltage drop across each resistor in the circuit described in question 17?
Last Answer : E1 = 80 volts. E2 = 240 volts. E3 = 320 volts
Description : When using Kirchhoff’s voltage law, how are voltage polarities assigned to the voltage drops across resistors?
Last Answer : The point at which current enters the resistor is assigned a negative polarity and the point at which current leaves the resistor is
Description : What is the voltage drop across the resistor in an RC charging circuit when the charge on the capacitor is equal to the battery voltage?
Last Answer : Zero.
Description : At what instant does the greatest voltage appear across the resistor in a series RC circuit when the capacitor is charging?
Last Answer : At the instant of the initiation of the action.
Description : A voltage of 30 V is applied across a colour coded carbon resistor with first, second and third rings of blue, black and yellow colurs. What is the cu
Last Answer : A voltage of 30 V is applied across a colour coded carbon resistor with first, second and ... What is the current flowing through the resistor ?
Description : In the illustration, 12 volts is applied to the circuit where the resistance of R1 is 10 ohms and R2 is 10 ohms. what is the voltage across R2? EL-0036 A. 1.2 volts B. 2 volts C. 6 volts D. 12 volts
Description : As shown in the illustration if the applied voltage is 12 VDC, the resistance of R1 is 110 ohms, and R2 is 10 kohms what is the voltage measured across R1 EL-0036 A. 11.86 volts B. .131 volts C. 12 volts D. .673 volts
Last Answer : Answer: B
Description : If the line voltage to the controller shown in the illustration is 440 volts, what is applied across the control circuit? EL-0080 A. 110 volts B. 220 volts C. 440 volts D. 660 volts
Description : If the line voltage to the controller shown in the illustration is 440 volts, what voltage is applied across the motor when contacts 'S' close? EL-0080 A. 110 volts B. 220 volts C. 440 volts D. 660 volts
Description : Autotransformer starters or compensators are sometimes used with polyphase induction motors to _____________. A. reduce the voltage applied to the motor during the starting period B. increase the voltage for ' ... to be either stepped up or down, depending on the application, to ensure full torque
Description : Three capacitors with different capacitances are connected in series. Which of the following statements is TRUE? w) All three of the capacitors have the same potential difference between their plates. x ... y) The capacitance of the system depends on the voltage applied across the three capacitors.
Last Answer : ANSWER: X -- THE MAGNITUDE OF THE CHARGE IS THE SAME ON ALL OF THE CAPACITOR PLATES
Description : A permanent magnet moving coil instrument gives full scale deflection of 25mA when a voltage of 75mV is applied across it. Calculate: (i) Resistance of shunt required for full scale deflection of 150 A. (ii) Series resistance for full scale deflection of 500 V.
Last Answer : Answer :
Last Answer : Req= (1/1200 +1/560 + 1/2.1)^-1 = 2.1 ohms RT= 2.1 + 7.8 = 9.9 ohms IT = V/R = 24/9.9 = 2.4 A Veq= R I = 2.1 2 ... 7.8 = 12.096 w = 44.928 w _________________________________________ By: Ellis-Junior Kamatjipose [email protected]