Description : Universal motors will operate on AC or DC current, and are generally found in _____________. A. portable tools B. large pump motors C. turbo electric main motors D. forced draft fans
Last Answer : Answer: A
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 : Motors, switches, voltage regulators, generators, etc., are a few examples of emi sources. What type of emi comes from these sources?
Last Answer : Man-made.
Description : Why are shaded-pole motors used to drive only very small devices?
Last Answer : They have very weak starting torques.
Description : How do split-phase induction motors become self-starting?
Last Answer : By using combinations of inductance and capacitance to apply out-of phase currents in starting windings.
Description : What are the three basic types of ac motors?
Last Answer : Series, synchronous, induction.
Description : A person with 'AB' blood group is sometimes called a universal recipient because of the – (1) lack of antigen in his blood (2) lack of antibodies in his blood (3) lack of both antigens and antibodies in his blood (4) presence of antibodies in his blood
Last Answer : (2) lack of antibodies in his blood
Description : A network system allows dissimilar machines to do what within one universal system?
Last Answer : Exchange information.
Description : As shown in the illustration, the electrical symbol is used to indicate which of the listed types of motors? EL-0054 A. Shunt motor. B. Series motor. C. Compound motor. D. Tri-field motor.
Last Answer : Answer: C
Description : In the construction of D.C. motors, parts of both the series and shunt fields are wound on the _____________. A. opposite main pole B. rotor core C. interpole D. same main pole
Last Answer : Answer: D
Description : Which of the following operating characteristics for DC motors is considered to give high starting torque? A. series B. shunt C. cumulative-compound D. differential-compound
Description : Shunt, series, and compound wound motors, are all DC motors designed to operate from _____________. A. constant potential, variable current DC sources B. variable potential, constant current DC ... C. variable potential, variable current DC sources D. constant potential, constant current DC sources
Description : Which of the following types of DC motors has its field connected in parallel with its armature? A. Counter EMF B. Shunt C. Salient pole D. Series
Last Answer : Answer: B
Description : Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.
Last Answer : Ans: B Because reversal of Ia would also mean reversal of field and hence of Eb
Description : As compared to shunt and compound DC motors, the series DC motor will have the highest torque because of its comparatively ____________ at the start. (A) Lower armature resistance. (B) Stronger series field. (C) Fewer series turns. (D) Larger armature current.
Last Answer : (D) Larger armature current.
Description : As compared to shunt and compound motors, series motor has the highest torque because of its comparatively .......... at the start.
Last Answer : As compared to shunt and compound motors, series motor has the highest torque because of its comparatively stronger series field at the start.
Last Answer : During rheostat braking of D.C. series motors motor is run as a generator.
Description : In case of conductively compensated D.C. series motors, the compensating winding is provided?
Last Answer : In case of conductively compensated D.C. series motors, the compensating winding is provided in series with armature winding.
Last Answer : When two D.C. series motors are connected in parallel, the resultant speed is normal speed.
Last Answer : In a capacitor start and run motors the function of the running capacitor in series with the auxiliary winding is to improve power factor.
Description : Sound waves transmitted from a source are sometimes weak when they reach the detector. What instrument is needed to boost the weak signal?
Last Answer : An amplifier.
Description : What is the unit of conductance and what other term is sometimes used?
Last Answer : NThe mho (v), siemens
Description : Sometimes it's necessary, but why should you avoid using cotton swabs when cleaning a magnetic tape transport?
Last Answer : Cotton swabs are not lint free.
Description : The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. (A) universal (B) synchronous (C) DC shunt (D) two-phase
Last Answer : Ans: A Universal motor has same characteristics as DC series motor and also known as an a.c series motor.
Description : What is the arrangement of both series and shunt components called?
Last Answer : Combination peaking.
Description : What is the condition of the diode in a series limiter when an output is developed? In a parallel limiter?
Last Answer : Conducting, cutoff.
Description : How can a series-positive limiter be modified to limit unwanted negative portions of the input signal?
Last Answer : Biasing.
Description : Which portion of a sine-wave input is retained in the output of a series-negative limiter?
Last Answer : Positive.
Description : Which portion of a sine-wave input is retained in the output of a series-positive limiter?
Last Answer : Negative.
Description : What determines whether these components are considered series or shunt?
Last Answer : . The relationship of the components to the output-signal path.
Description : In a series-RLC circuit, what is the condition of the circuit if there is high impedance, low current, and low reactance voltages
Last Answer : Nonresonant (circuit is either above or below resonance)
Description : Is an ammeter connected in series or in parallel with the circuit under test?
Last Answer : . In series.
Description : If inductance increases in a series LR circuit, what happens to true power?
Last Answer : It decreases.
Description : In a full-wave voltage doubler, are the capacitors connected in series or in parallel with the output load?
Last Answer : In parallel.
Description : When a series voltage regulator is used to control output voltages, any increase in the input voltage results in an increase/a decrease (which one) in the resistance of the regulating device.
Last Answer : An increase.
Description : In a capacitor filter, is the capacitor in series or in parallel with the load?
Last Answer : Parallel.
Description : What term is used for a series of overshoots in a servo system?
Last Answer : Hunting.
Description : In a series-connected duplexer, what tube (tr or atr), if any, fires during the receive cycle?
Last Answer : Neither fires.
Description : A shunt type voltage regulator is connected in series/parallel with the load resistance.
Last Answer : Parallel
Description : When a series voltage regulator is used to control output voltages, any increase in the input voltage results in an increase/a decrease in the resistance of the regulating device.
Last Answer : Increase.
Description : In a capacitor filter, is the capacitor in series or parallel with the load?
Description : For a diode to act as a rectifier, should it be connected in series or parallel with the load?
Last Answer : Series.
Description : What is the impedance of a crystal at its resonant frequency when it is used in the series mode?
Last Answer : Minimum.
Description : What is the difference between the series-fed and the shunt-fed Hartley oscillator?
Last Answer : In the series-fed Hartley oscillator, dc flows through the tank circuit.
Description : Name the two series circuits that exist in a diode circuit.
Last Answer : Filament and plate.
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 formula for determining total reactance in a series circuit where the values of XC and XL are known?
Last Answer : X = XL – XC or X = XC - XL
Description : What is the value of Z in a series ac circuit where XL = 6ohms, XC = 3ohms, and R = 4ohms?
Description : What advantage does a shunt motor have over a series motor?
Last Answer : It maintains a constant speed under varying loads.
Description : What is the main advantage of a series motor?
Last Answer : High torque (turning force) at low speed.