Description : What is the term for the opposition that a capacitor presents to ac?
Last Answer : Capacitive reactance.
Description : What is the opposition to current flow in an AC circuit caused by an inductor called?
Last Answer : Need answer
Description : What term is given to total opposition to ac in a circuit?
Last Answer : Impedance
Description : What is the term for the number of times per second that tank circuit energy is either stored in the inductor or capacitor?
Last Answer : Natural frequency or resonant frequency (f r).
Description : In an a.c. circuit that contains both an inductor and a capacitor, what term is used for the difference between the individual reactances?
Last Answer : Resultant reactance.
Description : What effect does an increase in capacitance have on a capacitor’s opposition to current flow?
Last Answer : Opposition to current flow decreases.
Description : What is the formula used to compute the value of this opposition?
Last Answer : XL = 2πfL.
Description : Which of the following statements concerning AC circuits is correct? A. The power factor of a resistive circuit is always zero. B. True power in an inductive circuit always equals apparent power. ... . D. Total opposition to the flow of alternating current depends upon the amount of reactive power.
Last Answer : Answer: C
Description : How does a capacitor and an inductor react to (a) low frequency and (b) high frequency?
Last Answer : At low-frequency, a capacitor acts as an open and an inductor acts as a short. At high-frequency, a capacitor acts as a short and an inductor acts as an open.
Description : When the magnetic field of the inductor is completely collapsed, where is the energy of the tank circuit stored?
Last Answer : . Capacitor.
Description : If the inductor and capacitor values are increased, what happens to the resonant frequency?
Last Answer : Decreases.
Description : When you are testing an inductor with a Hay bridge, the characteristics of the inductor are compared with what type of device?
Last Answer : A standard capacitor
Description : Which oscillator uses a tapped inductor for feedback?
Last Answer : Hartley.
Description : State three types of power loss in an inductor.
Last Answer : Copper loss; hysteresis loss; eddy-current loss.
Description : What is the phase relationship between current and voltage in an inductor?
Last Answer : Current lags voltage by 90° (ELI).
Description : What effect does an inductor have on a change in current?
Last Answer : An inductor opposes a change in current.
Description : Is the current flow through an inductor directly proportional or inversely proportional to its inductance value?
Last Answer : Directly proportional.
Description : A Hay bridge measures inductance by comparing an inductor to what component?
Last Answer : A capacitor.
Description : In a series `LCR` circuit the frequency of a `10 V`, `AC` voltage soure is adjusted in such a fashion that the reactance of the inductor meausers `15
Last Answer : In a series `LCR` circuit the frequency of a `10 V`, `AC` voltage soure is adjusted in such a ... the series combination of `L` and `C`will be:
Description : The potentiak difference across a 2H inductor as a function of time is shown in the figure. At time t=0, current is zero. Current versus time graph ac
Last Answer : The potentiak difference across a 2H inductor as a function of time is shown in the figure. At time t=0, ... across the inductor will be A. B. C. D.
Description : Refers to an ac bridge for measuring the inductance and Q of an inductor in terms of resistance, frequency and a standard capacitance.
Last Answer : hay bridge
Description : Describe the operation of inductor with sinusoidal AC voltage as input. Draw waveform for voltage across and current through the inductor. Draw its phasor representation.
Last Answer : An alternating voltage is applied to a purely inductive coil, a back e.m.f. is produced due to self-inductance of the coil. The back e.m.f. at every step, opposes the rise of fall of current through the coil ... drop, the applied voltage has to overcome this self induced e.m.f. only.
Description : The display screen of a spectrum analyzer presents a graphic plot of what two signal characteristics?
Last Answer : Power and frequency.
Description : With reference to the conduct of government business in the Parliament of India, the term 'closure' refers to - (1) suspension of debate at the terminatan of a day's sitting of the Parliament ... session (4) refusal on the part of tie Government to have the opposition look at important documents
Last Answer : (1) suspension of debate at the terminatan of a day's sitting of the Parliament Explanation: "Closure" is one of the means by which a debate may be brought to a close by a majority decision of the FIouse, even though all members wishing to speak have not done so.
Description : Antithrombin III deficiency is a commonly observed hypercoaguable state. Which of the following statement(s) is/are true concerning this condition? a. A patient with this deficiency usually ... involves acutely the administration of fresh frozen plasma followed by long-term treatment with Coumadin
Last Answer : Answer: a, b, c, d Antithrombin III deficiency accounts for about 2% of venous thrombotic event. This deficiency has been described in patients with pulmonary embolism, mesenteric venous ... is established, fresh frozen plasma should be administered followed by long-term treatment with Coumadin
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 leads in a simple synchro system are connected to the ac power line?
Last Answer : The rotor leads.
Description : When used for ac current control, during which alternation of the ac cycle does the TRIAC control current flow?
Last Answer : During both alternations.
Description : What is the basic difference between the primaries of ac and dc rate generators?
Last Answer : The method of primary excitation (ac and permanent magnet).
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 : Most shipboard distribution systems use ac power that has what number of phases?
Last Answer : Three.
Description : What are the electrons called that give up energy to the ac field in a magnetron?
Last Answer : Working electrons.
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 : 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 : 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 : 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 : An ac voltage is applied across a diode. The tube will conduct when
Last Answer : Positive.
Description : What is the difference between calculating impedance in a series ac circuit and in a parallel ac circuit?
Last Answer : In a series circuit impedance is calculated from the values of resistance and reactance. In a parallel circuit, the values of resistive current and reactive current must be used to calculate total impedance.
Description : What is the reactive power in an ac circuit?
Last Answer : Reactive power is the power returned to the source by the reactive components of the circuit.
Description : What is the true power in an ac circuit?
Last Answer : True power is the power dissipated in the resistance of the circuit or the power actually used in the circuit.
Description : What is the value of Z in a series ac circuit where XL = 6ohms, XC = 3ohms, and R = 4ohms?
Last Answer : X = XL – XC or X = XC - XL
Description : What component causes a generator to produce dc voltage rather than ac voltage at its output terminals?
Last Answer : A commutator
Description : Why should you avoid using ac-powered test equipment when wearing a wrist strap?
Last Answer : For your own safety.
Description : Why is the dc scale on a multimeter different than the ac scale?
Last Answer : The meter movement reacts to average ac voltage and current and the effective value is desired.
Description : List three meter movements that can measure either ac or dc without the use of a rectifier.
Last Answer : Electrodynamic, moving vane, and hot-wire or thermocouple.
Description : What value is indicated on the scale of an ac meter?
Last Answer : Effective value (rms).
Description : What value does a meter movement react to (actually measure) when measuring ac?
Last Answer : Average value.
Description : How can a d’Arsonval meter movement be adapted for use as an ac meter?
Last Answer : By the use of a rectifier