Electrical Basics Objective Part-5 Questions

[1] A diode can be used as a frequency multiplier because of itsA. Junction capacitanceB. Non linearityC. Avalanche voltageD. Forward breakoverE. Charge carrier concentration

Ans: B

[2] Which of the following is not a common form of data transmissionA. Polarization modulationB. Frequency modulationC. Amplitude modulationD. Phase modulationE. Pulse modulation

Ans: A

[3] A very brief, high voltage spike on an ac power line is called asA. A bleederB. An arcC. A transientD. An avalancheE. A clipped peak

Ans: C

[4] Which of the following is not characteristic of an oscillator?A. Negative feedbackB. Good output to input couplingC. Reasonably high transistor gainD. Alternating current signal outputE. Usefulness as a signal generator

Ans: A

[5] The other name for beta of BJT isA. Current amplification factorB. Voltage amplification factorC. Power amplification factorD. Maximum amplification frequencyE. Optimum amplification frequency

Ans:A [6] You can find the zener diode inA. The mixer in a superheterodyne receiverB. The PLL in a circuit for detecting FMC. The product detector in a receiver for SSBD. The voltage regulator in a power supplyE. The AF oscillator in an AFSK transmitter

Ans: D [7] When the bias in an FET stops the flow of current, the condition is calledA. Forward breakoverB. CutoffC. Reverse biasD. PinchoffE. Avalanche

Ans: D [8] The VA rating of a transformer is an expression ofA. The maximum frequency at which it can functionB. The type of core material it hasC. The voltage step-up or step-down ratioD. The impedance transfer ratioE. None of the above

Ans: E [9] In N-type semiconductor, the minority carriers areA. ElectronsB. ProtonsC. HolesD. Positrons

Ans: C [10] A disadvantage of a half wave rectifier is the fact thatA. The output voltage is excessive compared to that of a full-wave rectifierB. The output current is excessive compared to that of a full-wave rectifier.C. The output waveform is harder to filter than is the case with a full wave rectifierD. It requires several expensive diodes, whereas a full wave rectifier requires only a single diode

Ans: C [11] A power gain of 30dB is equivalent to which amplification factor?A. 0.001B. 1/30C. 30D. 1000E. None of the above

Ans: D

Basic Electrical Engineering: Part-11

[1] The unit which indicates the rate at which energy is expended?A. WattB. Ampere-hourC. CoulombD. Volt

Ans: A [2] The peak voltage in an ac wave is alwaysA. Greater than the average voltageB. Less than the average voltageC. Greater than or equal to average voltageD. Less than or equal to the average voltage

Ans: C [3] When an electrical charge exists but there is no flow of current, the charge is said to beA. IonizingB. ElectronicC. StaticD. Atomic

Ans: C [4] As the number of turns in a coil that carries ac increases without limit, the current in the coil willA. Eventually become very largeB. Stay the sameC. Decrease, approaching zeroD. Be stored in the core material

Ans: C [5] As the number of turns in a coil increases, the reactance at a constant frequencyA. IncreasesB. DecreasesC. Stays the same

D. Is stored in the core material

Ans: A [6] In an RL circuit, as the ratio of inductive reactance to resistance (XL/R) decreases, the phase angleA. IncreasesB. DecreasesC. Stays the sameD. Becomes alternately positive and negative

Ans: B

[7] The best filter for a power supply isA. A capacitor in seriesB. A choke in seriesC. A capacitor in series and a choke in parallelD. A capacitor in parallel and a choke in series

Ans: D [8] Voltage regulation can be achieved by a zener diode connected inA. Parallel with the filter output, forward biasedB. Parallel with the filter output, reverse biasedC. Series with the filter output, forward biasedD. Series with the filter output, reverse biased

Ans: B [9] A current surge takes place when a power supply is first turned on becauseA. The transformer core is suddenly magnetizedB. The diodes suddenly start to conductC. The filter capacitor must be initially chargedD. Arching takes place in the power switch

Ans: C [10] A dc electromagnetA. Has constant polarityB. Requires an air coreC. Cannot be used to permanently magnetize anythingD. Does not attract or repel permanent magnet

Ans: A [11] In a multi-stage RC coupled amplifier the coupling capacitor______________A) Limits the low frequency responseB) Limits the high frequency responseC) Does not affect the frequency responseD) Block the DC component without affecting the frequency response

Ans: A [12] It is required to measure temperature in the range of 13000 deg C to 15000 deg c. The most suitable thermocouple to be used as a transducer would be?a) Chromel - constantanb) Iron - constantanc) Chromel - alumeld) Platinum- rhodium Ans: D [13] Telemetering is a method of?a) Counting pulses sent over long distancesb) Transmitting pictures from one place to anotherc) Transmitting information concerning a process over a distanced) None

Ans: C [14] A dc to dc converter having an efficiency of 80% is delivering 16W to a load. If the converter is generating an output of 200V from an input source of 20V, then the current drawn from the source will be?a) 0.1Ab) 0.5Ac) 1.0Ad) 10.0A Ans: C

[15] The location of lighting arrestor is?a) Near the transformerb) Near the circuit breakerc) Away from the transformerd) None

Ans: D