Electronics
When a transistor is in saturation. A. VCE = VCC. B. IC = 0 A. C. VCE = 0 V. D. VCE = ½ VCC
. C. VCE = 0 V.
Which of the following biasing techniques produces the most unstable Q point? A. voltage divider bias. B. emitter bias. C. collector bias. D. base bias.
. D. base bias.
Semiconductors which are considered to be low-power or small signal have power dissipation ratings of:
1 W or less
What is the output voltage of a silver cadmium cell?
1.1 V
What is the output voltage of a carbon-zinc cell?
1.5 V
There are approximately how many free carriers in a cubic centimeter of intrinsic silicon material at room temperature?
1.5 x 10¹⁰
The magnetic field outside a long straight current-carrying wire depends on the distance R from the wire axis according to:
1/R
If R is the distance from a magnetic dipole, then the magnetic field it produces is proportional to:
1/R³
What is the minimum ampere capacity of panel box used today?
100
Silicon resistivity is about _______.
100 Ω-cm
A radio equipment will be used 70% at 50 amperes rating for 5 hours, how much capacity of a dry battery is needed?
175 Ah
A two-pole, three-phase motor has_______ field poles.
2
Window comparator requires how many op-amps?
2
If 2 V is applied to a 20 dB attenuator, the level will be:
200 mV
What is the maximum efficiency of half wave rectification?
41%
How many silver zinc cells in series are needed for a 9 V battery?
6
A half wave rectifier circuit utilizing one half of an AC input cycle has a ripple frequency in its output equivalent to _______.
60 cps
What is the output for a four lead acid cells?
8.4 V
What piece of test equipment besides an oscilloscope can be used to indicate pulse conditions in a digital-logic circuit?
A logic probe
The phase angle of an LC circuit at resonance is A. 0 degrees C. +90 degrees. B. 180 degrees. D. - 90 degrees.
A. 0 degrees
One ampere of current corresponds to A. 1 C/1 s B. 1 J/1 C C. 6.25 X 1018 electrons D. 0.16 x 10-18 C/s
A. 1 C/1 s
Twelve 1 Ω resistance are used as edges to form a cube. What is the resistance between two diagonally opposite corners of the cube? A. 5/6 Ω C. 1 Ω B. 6/5 Ω D. 3/2 Ω
A. 5/6 Ω
According to the absorptive Laws of Boolean algebra, expression (A+AB) equals A. A C. B B. AB D. A
A. A
A decoder is an MSI circuit whose output lines are controlled by: A. A binary input select code B. A similar set of input lines C. An output enable D. A clock input
A. A binary input select code
If the reference point is changed to the earth point then any voltage taken w.r.t. the earth is known as A. Absolute potential B. Earth ground C. Relative voltage D. Absolute point
A. Absolute potential
Which of the following statement is false? A. An air capacitor is normally a variable type B. A paper capacitor generally has a shorter service life than most other types of capacitor C. An electrolytic capacitor must be used only on a.c. supplies D. Plastic capacitors generally operate satisfactorily under conditions of high temperature
A. An air capacitor is normally a variable type
Which of the following statement is false? A. An air capacitor is normally a variable type B. A paper capacitor generally has a shorter service life than most other types of capacitor C. An electrolytic capacitor must be used only on a.c. supplies D. Plastic capacitors generally operate satisfactorily under conditions of high temperature
A. An air capacitor is normally a variable type
What is a relay? A. An electrically-controlled switch B. A current controlled amplifier C. An optical sensor D. A pass transistor
A. An electrically-controlled switch
The product of the readings of an AC voltmeter and AC ammeter is called: A. Apparent power. B. True power. C. Power factor. D. Current power.
A. Apparent power.
In a common-emitter amplifier, what happens to the voltage gain, Av, when a load resistor, RL, is connected to the output? A. Av decreases. B. Av increases. C. Av doesn't change. D. Av doubles
A. Av decreases.
Assertion (A): The reverse saturation current in a semiconductor diode is 4 nA at 20°C and 32 nA at 50°C. Reason (R): The reverse saturation current in a semiconductor diode doubles for every 10°C rise in temperature. A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true
A. Both A and R are true and R is correct explanation of A
A potentiometer is used to: A. Compare voltages B. Measure power factor C. Compare currents D. Measure phase sequence
A. Compare voltages
A ferromagnetic material: A. Concentrates magnetic flux lines within itself. B. Increases the total magnetomotive force around a current-carrying wire. C. Causes an increase in the current in a wire. D. Increases the number of ampereturns in a wire.
A. Concentrates magnetic flux lines within itself.
If a resistance to which a constant voltage is applied is halved, what power dissipation will result? A. Doubled B. Halved C. Stays the same D. Quadrupled
A. Doubled
Which of the following conditions are needed to properly bias an npn transistor amplifier? A. Forward bias the base/emitter junction and reverse bias the base/collector junction. B. Forward bias the collector/base junction and reverse bias the emitter/base junction C. Apply a positive voltage on the ntype material and a negative voltage on the p-type material. D. Apply a large voltage on the base.
A. Forward bias the base/emitter junction and reverse bias the base/collector junction.
If a NAND latch has a 1 on the SET input and 0 on the CLEAR input, then the SET input goes to 0, the latch will be: A. HIGH B. LOW C. Invalid D. None of these
A. HIGH
The alpha(dc) of a transistor equals A. IC/LE. C. IB/LC. B. IE/LC. D. IC/IB
A. IC/LE.
In a parallel RL circuit, A. IL lags IR by 90 degrees B. IL leads IR by 90 degrees C. IL and IR are in phase. D. IR lags IL by 90 degrees
A. IL lags IR by 90 degrees
With permeability tuning, moving the core further into a solenoidal coil: A. Increases the inductance B. Reduces the inductance C. has no effect on the inductance, but increases the current- carrying capacity of the coil D. Raises the frequency
A. Increases the inductance
The purpose of the I layer in a PIN diode is to: A. Minimize the diode capacitance B. Optimize the avalanche voltage C. Reduce the forward break over voltage D. Increase the current through the diode
A. Minimize the diode capacitance
Which of the following is neither a basic physical law nor derivable from one? A. Ohm's law B. Coulomb's law C. Kirchhoff's first law D. Kirchhoff's second law
A. Ohm's law
What is the term for the time required for the current in an RL circuit to build up to 63.2% of the maximum value? A. One time constant. B. An exponential period of one. C. A time factor of one. D. One exponential rate
A. One time constant.
Selenium works especially well in: A. Photocells B. High-frequency detectors C. Radio-frequency power amplifiers D. Voltage regulators
A. Photocells
A photodiode, when not used as a photovoltaic cell, has: A. Reverse bias B. No bias C. Forward bias D. Negative resistance
A. Reverse bias
When a P-N junction does not conduct, it is: A. Reverse biased B. Forward biased C. Biased past the break over voltage D. In a state of avalanche effect
A. Reverse biased
What type of wave is made up of sine waves at the fundamental frequency and all the harmonics? A. Sawtooth wave. B. Square wave. C. Sine wave. D. Cosine wave.
A. Sawtooth wave.
Clock periods are measured from: A. Similar points on the clock waveform B. From the low level to the high level C. From the high level to the low level D. From the time the clock pulse is at 50% of its low-to-high transition until it is at 50% of its high-to-low transition
A. Similar points on the clock waveform
What type of wave is made up of sine waves of the fundamental frequency and all the odd harmonics? A. Square. C. Sine. B. Cosine. D. Tangent
A. Square.
In which type of amplifier is the input applied to the emitter and the output taken from the collector? A. The common-base amplifier B. The common-emitter amplifier C. The common-collector amplifier D. The emitter follower
A. The common-base amplifier
When a P-N junction is reversebiased, the capacitance depends on all of the following except: A. The frequency B. The width of the depletion region. C. The cross-sectional area of the junction D. The type of semiconductor material
A. The frequency
A strong permanent magnet is plunged into a coil and left in the coil. What is the effect produced on the coil after a short time? A. There is no effect B. The insulation of the coil burns out C. A high voltage is induced D. The coil winding becomes hot
A. There is no effect
The rise time of a signal is the time: A. To make a transition from a low level to a high level B. To make a transition from a high level to a low level C. For the output signal to start making a transition to a high level from the time an input signal causes the transition to occur D. Between midpoints of a square wave signal
A. To make a transition from a low level to a high level
In a parallel RC circuit, A. VA and IR are in phase. B. VA and IC are in phase. C. IC and IR are in phase. D. VA and IR are 90 degree out of phase
A. VA and IR are in phase.
For an inductor in a sine-wave ac circuit, A. VL leads iL by 90° B. VL lags iL by 90° C. VL and iL are in phase. D. None of the above
A. VL leads iL by 90°
In a series RLC circuit, A. XL and XC are 180 out of phase. B. IL and IC are 180 out of phase. C. IL and XC are 180 out of phase. D. IL and XC are in phase.
A. XL and XC are 180 out of phase.
Which of the following can provide a higher Q? A. a higher L/C ratio. B. a lower L/C ratio. C. more resistance in series with the coil. D. Either B or C.
A. a higher L/C ratio.
The total capacitance of two or more capacitors in series is: A. always less than that of the smallest capacitor B. always greater than that of the largest capacitor C. found by adding each of the capacitances together D. found by adding the capacitances together and dividing by their total number
A. always less than that of the smallest capacitor
Two bar magnets are placed parallel to each other and about 2 cm apart, such that the south pole of one magnet is adjacent to the north pole of the other. With this arrangement, the magnets will: A. attract each other B. have no effect on each other C. repel each other D. lose their magnetism
A. attract each other
Two metal plates separated by air form a 0.001 microF capacitor. Its value may be changed to 0.002 microF by: A. bringing the metal plates closer together B. using the plates smaller in size C. moving the plates apart D. touching the two plates together
A. bringing the metal plates closer together
The capacitance of a capacitor is the ratio A. charge to p.d. between plates B. p.d. between plates to plate spacing C. p.d. between plates to thickness of dielectric D. p.d. between plates to charge
A. charge to p.d. between plates
4. In a class B push-pull amplifier, the transistors are biased slightly above cutoff to avoid A. crossover distortion B. unusually high efficiency C. negative feedback D. a low input impedance
A. crossover distortion
Self-inductance occurs when the: A. current is changing B. circuit is changing C. flux is changing D. resistance is changing
A. current is changing
A resistive and a capacitive load of equal magnitude is connected in series, determine the phase difference between the voltage and the current. A. current leads the voltage by 45° B. current lags the voltage by 45° C. current leads the voltage by 90° D. current lags the voltage by 90°
A. current leads the voltage by 45°
When the collector current in a transistor is zero, the transistor is A. cut off. B. saturated. C. operating in the breakdown region. D. Either B or C
A. cut off.
A relay can be used to: A. decrease a current in a circuit B. control a circuit more readily C. increase a current in a circuit D. control a circuit in a distance
A. decrease a current in a circuit
When either L or C is increased, the resonant frequency of an LC circuit A. decrease. B. increases. C. doesn't change. D. it cannot be determined.
A. decrease.
Which is the wrong statement? The magnetizing force at the center of a circular coil varies A. directly as the number of its turns B. directly as the current C. directly as its radius D. inversely as its radius
A. directly as the number of its turns
In an n-p-n transistor, the majority carriers in the base are A. electrons B. holes C. both holes and electrons D. either holes or electrons
A. electrons
There is a force of attraction between two current-carrying conductors when the current in them is: A. in opposite direction B. in the same direction C. of different magnitude D. of the same magnitude
A. in opposite direction
The effect on an air gap in a magnetic circuit is to: A. increase the reluctance B. reduce the flux density C. divide the flux D. reduce the magnetomotive force
A. increase the reluctance
The total resistance in a parallel circuit: A. is always less than the smallest resistance B. depends upon the voltage drop across each branch C. could be equal to the resistance of one branch D. depends upon the applied voltage
A. is always less than the smallest resistance
In digital circuits Schottky transistors are preferred over normal transistor because of their A. lower propagation delay B. higher propagation delay C. lower power dissipation D. higher power dissipation
A. lower propagation delay
A logic gate is an electronic circuit which A. makes logic decision B. allows electron flow only in one direction C. works on binary data D. alternates between 0 and 1 values
A. makes logic decision
An inductor and a capacitor are connected in parallel. At the resonant frequency the resulting impedance is: A. maximum B. minimum C. totally reactive D. totally inductive A. maximum B. minimum C. totally reactive D. totally inductive
A. maximum
The total line current, IT, of a parallel LC circuit at resonance is A. minimum. B. maximum. C. equal to IL and Ic. D. Q times larger than IL or IC
A. minimum.
The main advantage of CMOS logic family over the TTL family is its A. much reduced power B. increased speed of operation C. extremely low cost D. series base resistor
A. much reduced power
A parallel circuit at resonance would mean, the circuit is A. resistive B. inductive C. reactive D. capacitive
A. resistive
A series circuit at resonance would mean, the circuit is A. resistive C. inductive B. capacitive D. reactive
A. resistive
The ends of a load line drawn on a family of curves determine: A. saturation and cutoff B. the operating point C. the power curve D. the amplification factor
A. saturation and cutoff
In a C-E configuration, an emitter resistor is used for: A. stabilization B. ac signal bypass C. collector bias D. higher gain
A. stabilization
In what operating region does the collector of a transistor act like a current source? A. the active region. B. the saturation region. C. the cutoff region. D. the breakdown region.
A. the active region.
To forward-bias a diode, A. the anode voltage must be positive with respect to its cathode. B. the anode voltage must be negative with respect to its cathode. C. the cathode voltage must be positive with respect to its anode. D. Either A or B.
A. the anode voltage must be positive with respect to its cathode.
Which of the following transistor amplifiers has the lowest output impedance? A. the common-collector amplifier. B. the common-base amplifier. C. the common-emitter amplifier. D. None of the above.
A. the common-collector amplifier.
Which of the following transistor amplifier configurations provides a 180 phase shift between the ac input and output voltages? A. the common-emitter amplifier. B. the emitter follower. C. the common-base amplifier. D. the common-collector amplifier.
A. the common-emitter amplifier
The polarity of a resistor's voltage drop is determined by A. the direction of current through the resistor. B. how large the resistance is. C. how close the resistor is to the voltage source. D. how far away the resistor is from the voltage source
A. the direction of current through the resistor.
Which region in a transistor is the most heavily region? A. the emitter region. B. the collector region. C. the gate region. D. the base region.
A. the emitter region.
In an R-L circuit connected to an alternating sinusoidal voltage, size of transient current primarily depends on A. the instant in the voltage cycle at which circuit is closed B. the peak value of steady-state current C. the circuit impedance D. the voltage frequency
A. the instant in the voltage cycle at which circuit is closed
When a voltage is applied to a semiconductor crystal then the free electrons will flow. A. towards positive terminal B. towards negative terminal C. either towards positive terminal or negative terminal D. towards positive terminal for 1 μs and towards negative terminal for next 1 μs
A. towards positive terminal
A p-type semiconductor is a semiconductor doped with A. trivalent impurity atoms. B. impurity atoms whose electron valence is _ 4. C. pentavalent impurity atoms. D. None of the above.
A. trivalent impurity atoms.
A unique operating feature of ECL circuit is its A. very high speed B. high power dissipation C. series base resistor D. compatibility with other logic series
A. very high speed
What is the simplest and commonly used method to switch off an SCR?
Anode-current interruption
Which one of the following is not a part of CRT?
Armature
What is the unit of reluctance in SI?
At/Wb
What is the power factor (PF) of a purely resistive ac circuit? A. 0. B. 1. C. 0.707. D. Without values, it cannot be determined.
B. 1.
The charge on a single electron is A. 6.25 x 10-18 C B. 1.6 x 10-19 C C. 1.6 x 10-21 C D. 3.14 x 10-6 C
B. 1.6 x 10-19 C
If a multiplexer circuit has four input lines and a single output line, how many bits of line select code are required? A. 0 C. 1 B. 2 D. 4
B. 2
The typical number of bits in a static memory location is: A. 1 C. 2 B. 8 D. 16
B. 8
After two-time constants, the capacitor in an RC circuit is charged to what percentage of the supply voltage? A. 36.8 % C. 63.2 % B. 86.5 % D. 95 %
B. 86.5 %
What is a sine wave? A. A constant-voltage, varyingcurrent wave. B. A wave whose amplitude at any given instant can be represented by the projection of a point on a wheel rotating at a uniform speed. C. A wave following the laws of the trigonometric tangent function. D. A wave whose polarity changes in a random manner.
B. A wave whose amplitude at any given instant can be represented by the projection of a point on a wheel rotating at a uniform speed.
The dual of the statement (A+1)=1 is A. A.1 = A B. A.0 = 0 C. A+A = A D. A.A = 1
B. A.0 = 0
What will happen when the power factor of a circuit is increased? A. Reactive power increases B. Active power increases C. Both active and reactive powers increases D. Both active and reactive powers decreases
B. Active power increases
In which region of a CE bipolar transistor is collector current almost constant? A. Saturation region B. Active region C. Breakdown region D. Both saturation and active region
B. Active region
A semiconductor material is made into N type by: A. Adding an acceptor impurity B. Adding a donor impurity C. Injecting electrons D. Taking electrons away
B. Adding a donor impurity
A static memory will store information: A. Even when power is not applied to the memory B. As long as power is applied to the memory C. As long as power is applied and the memory is refreshed periodically D. None of these
B. As long as power is applied to the memory
Assertion (A): The conductivity of p type semiconductor is higher than that of intrinsic semiconductor. Reason (R): The addition of donor impurity creates additional energy levels below conduction band. A. Both A and R are true and R is correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true
B. Both A and R are true but R is not a correct explanation of A
Holes flow the opposite way from electrons because: A. Charge carriers flow continuously B. Charge carriers are passed from atom to atom C. They have the same polarity D. Holes flow in the same direction as electrons
B. Charge carriers are passed from atom to atom
The hold time for a D-type flip-flop is the time the: A. Data will be held on the output after a clock signal B. Data must be held on the input after a clock edge C. Clock must be high D. Clock must be low
B. Data must be held on the input after a clock edge
The force between two electrically charged objects is called: A. Electromagnetic deflection. B. Electrostatic force. C. Magnetic force. D. Electroscopic force.
B. Electrostatic force.
The endpoints of a dc load line are labeled A. ICQ and VCEQ. B. IC(Sat) and VCE(off). C. IC(off) and VCE(Sat). D. None of the above.
B. IC(Sat) and VCE(off).
In a transistor, which current is the largest? A. IC. C. IB. B. IE. D. ID.
B. IE.
In a low Q parallel resonant circuit, when XL = Xc. A. IL = IC. B. IL is less than IC. C. IC is less than IL. D. IL is more than IC.
B. IL is less than IC.
A diode detector: A. Is used in power supplies B. Is employed in some radio receivers C. Is used commonly in high-power radio transmitters D. Changes dc into ac
B. Is employed in some radio receivers
When a diode is forward-biased, the anode: A. Is negative relative to the cathode B. Is positive relative to the cathode C. Is at the same voltage as the cathode D. None of the above
B. Is positive relative to the cathode
What happens to reactive power in a circuit that has both inductors and capacitors? A. It is dissipated as heat in the circuit. B. It alternates between magnetic and electric fields and is not dissipated. C. It is dissipated as inductive and capacitive fields. D. It is dissipated as kinetic energy within the circuit
B. It alternates between magnetic and electric fields and is not dissipated.
The logic gate which produces a 0 or low-level output when one or both of the inputs are 1 is called ______ gate. A. AND C. OR B. NOR D. NAND
B. NOR
What is the term for the time required for the capacitor in an RC circuit to be charged to 63.2% of the supply voltage? A. An exponential rate of one. B. One time constant. C. One exponential period. D. A time factor of one.
B. One time constant.
Holes flow from: A. Minus to plus B. Plus to minus C. P-type to N-type material D. N-type to P-type material
B. Plus to minus
A sequential logic system has outputs that depend on: A. Only the inputs to the system at the current time B. Present as well as past inputs C. Memory device outputs independent of system inputs D. None of these
B. Present as well as past inputs
The equivalent wye element of 3 equal resistors each equal to R and connected in delta is A. R C. 3/2 R B. R/3 D. 3R
B. R/3
What electrical parameter is controlled by a potentiometer? A. Inductance B. Resistance C. Capacitance D. Field strength
B. Resistance
The capacitance of a varactor varies with: A. Forward voltage B. Reverse voltage C. Avalanche voltage D. Forward break over voltage
B. Reverse voltage
A static memory generally contains: A. No decoders B. Row decoders C. Column decoders D. Both row and column decoders
B. Row decoders
A flip-flop which can have an uncertain output state is: A. J-K flip-flop B. S-C flip-flop C. D flip-flop D. T flip-flop
B. S-C flip-flop
The purpose of the logic analyzer is to: A. Verify the logic operation of the gates in a system B. Sample and display system signals C. Analyze the functional logic operations of a system D. None of these
B. Sample and display system signals
Which of the following transistor amplifier configurations is often used in impedance-matching applications? A. The common-base amplifier B. The emitter follower C. The common-emitter amplifier D. The common-source amplifier
B. The emitter follower
To cause a three-state buffer to output 0 or 1 levels, the following must be true: A. The information must have been stored within the buffer B. The output enable must be true C. The output enable must be false D. The signal OE̅̅̅̅ must be at a logic 1
B. The output enable must be true
If a complex circuit is reduced to an equivalent circuit consisting of a single voltage source in series with a single resistor, this is an example of: A. Norton's theorem B. Thevenin's theorem C. Ohm's law D. Kirchhoff's law
B. Thevenin's theorem
The transient current in a loss-free LC circuit when excited from an ac source is a/an _______ sine wave. A. Overdamped B. Undamped C. Under damped D. Critically damped
B. Undamped
With voltage divider bias, how much is the collector-emitter voltage, VCE, when the transistor is cut off? A. VCE = 1.2 VCC. B. VCE = VCC. C. VCE= 0 V. D. None of the above.
B. VCE = VCC.
In an ac circuit with only series capacitors, A. VT leads IT by 90 degrees. B. VT lags IT by 90 degrees. C. each capacitor voltage drop leads IT by 90 degrees D. Both A and C
B. VT lags IT by 90 degrees.
The term "semiconductor" arises from: A. Resistor-like properties of metal oxides. B. Variable conductive properties of some materials. C. The fact that there's nothing better to call silicon. D. Insulating properties of silicon and GaAs.
B. Variable conductive properties of some materials.
The resonant frequency of an LC circuit is the frequency where A. XL = 0 ohms and XC = 0 ohms B. XL = XC C. XL and rs of the coil are equal. D. XL and Xc are in phase.
B. XL = XC
Voltage-divider bias provides: A. an unstable Q point B. a stable Q point C. a Q point that easily varies with changes in the transistor's current gain D. a Q point that is stable and easily varies with changes in the transistor's current gain
B. a stable Q point
Inductive reactance, XL, A. applies only to non-sinusoidal waveforms or dc. B. applies only to sine waves. C. applies to either sinusoidal or non-sinusoidal waveforms. D. is inversely proportional to frequency.
B. applies only to sine waves.
At very high temperatures the extrinsic semiconductors become intrinsic because A. drive in diffusion of dopants and carriers B. band to band transition dominants over impurity ionization C. impurity ionization dominants over band to band transition D. band to band transition is balanced by impurity ionization
B. band to band transition dominants over impurity ionization
To a first approximation, a forwardbiased diode is treated like a (n) A. open switch with infinite resistance. B. closed switch with a voltage drop of 0 V. C. closed switch in series with a battery voltage of 0.7 V. D. closed switch in series with a small resistance and a battery.
B. closed switch with a voltage drop of 0 V.
In an n-p-n transistor biased for operation in forward active region A. emitter is positive with respect to base B. collector is positive with respect to base C. base is positive with respect to emitter and collector is positive with respect to base D. none of the above
B. collector is positive with respect to base
An XOR gate produces an output only when its two inputs as A. high C. low B. different D. same
B. different
An inductor and a capacitor form a resonant circuit. If the value of the inductor is decreased by a factor of four, the resonant frequency will: A. increase by a factor of four B. increase by a factor of two C. decrease by a factor of two D. decrease by a factor of four
B. increase by a factor of two
The fan-in of a logic gate refers to the number of A. input devices that can be connected B. input terminals C. output terminals D. circuits output can drive
B. input terminals
A "high Q" resonant circuit is one which: A. carries a high quiescent current B. is highly selective C. has a wide bandwidth D. uses a high value inductance A. carries a high quiescent current B. is highly selective C. has a wide bandwidth D. uses a high value inductance
B. is highly selective
State which of the following is false. The capacitance of a capacitor A. is proportional to the cross sectional area of the plates B. is proportional to the distance between the plates C. depends on the number of plates D. is proportional to the relative permittivity of the dielectric
B. is proportional to the distance between the plates
The impedance of a parallel LC circuit at resonance is A. zero. B. maximum. C. minimum. D. equal to the rs of the coil
B. maximum.
An inductor and a capacitor are connected in series. At the resonant frequency the resulting impedance is: A. maximum B. minimum C. totally reactive D. totally inductive
B. minimum
A unique advantages feature of CMOS logic family is its A. use of NMOS circuits B. power dissipation in nanowatt range C. speed D. dependent on frequency for power dissipation
B. power dissipation in nanowatt range
The chief advantage of Schottky TTL logic family is its least A. power dissipation B. propagation delay C. fan-in D. noise immunity
B. propagation delay
When used as a voltage regulator, a zener diode is normally A. forward-biased. B. reverse-biased. C. not biased. D. None of the above
B. reverse-biased.
In Norton's Theorem, the short circuit current is obtained by A. opening the load terminals B. shorting the load terminals C. opening the voltage source D. shorting the voltage source
B. shorting the load terminals
A 5-ohm and 10-ohm resistor are connected in series across a dc voltage source. Which resistor will dissipate more power? A. the 5-ohm resistor. B. the 10-ohm resistor. C. It depends on how much the current is. D. They will both dissipate the same amount or power
B. the 10-ohm resistor.
In a transistor, which is the largest of all the doped regions? A. the emitter region. B. the collector region. C. the gate region. D. the base region.
B. the collector region.
hich type of transistor amplifier is also known as the emitter follower? A. the common-base amplifier. B. the common-collector amplifier. C. the common-emitter amplifier. D. None of the above.
B. the common-collector amplifier.
The ability of an LC circuit to supply complete sine waves when the input to the tank is only a pulse is called A. tuning. B. the flywheel effect. C. antiresonance. D. its Q.
B. the flywheel effect.
In a series circuit, the current, I, is A. different in each resistor. B. the same everywhere. C. the highest near the positive and negative terminals of the voltage source. D. different at all, the largest resistance has
B. the same everywhere.
The transients which are produced due to sudden but energetic changes from one steady state of a circuit to another are called ________ transients. A. initiation B. transition C. relaxation D. subsidence
B. transition
Emitter bias with two power supplies provides a A. very unstable Q point. B. very stable Q point. C. large base voltage. D. None of the above.
B. very stable Q point.
When a material becomes a superconductor, its resistivity becomes A. very small B. zero C. about 10% of normal value D. about 20% of normal value
B. zero
When the parallel resonant LC circuit is in series with the load and the series resonant circuit is shunted across the load, the filter behaves as _______.
Band Pass
What are the elements of unijunction transistors?
Base 1, base 2 and emitter
What single device converts chemical energy into electrical energy?
Battery
A half-adder can be constructed using:
Both Exclusive OR gate and AND gate
Which of the following characterizes CMOS logic?
Both P-channel and N-channel FETs
With an electromagnet,
Both more current and more coil turns mean a stronger magnetic field and if there is no current in the coil, there is no magnetic field.
A zener diode is connected so that:
Both the cathode is positive with respect to the anode and it is reversed bias
Efficient oscillators are those of what class?
C
If a resistor in a series circuit becomes open, how much is the voltage across each of the remaining resistors that are still good? A. Each good resistor has the full value of applied voltage. B. The applied voltage is split evenly among the good resistors. C. 0 V. D. It cannot be determined
C. 0 V.
In a bipolar transistor the barrier potential A. 0 B. a total of 0.7 V C. 0.7 V across each depletion layer D. 0.35 V
C. 0.7 V across each depletion layer
Rise and fall times are measured from: A. 50% points on a waveform B. 0 voltage level time to 1 voltage level time C. 10% to 90% points on the voltage transition D. The input signal to the output signal
C. 10% to 90% points on the voltage transition
What is the decimal equivalent of the hexadecimal number 3E8? A. 576 C. 1000 B. 1025 D. 8350
C. 1000
After two-time constants, the capacitor in an RC circuit is discharged to what percentage of the starting voltage? A. 86.5 % C. 13.5 % B. 63.2 % D. 36.8 %
C. 13.5 %
A branch current of +j250 mA represents A. 250 mA of inductive current. B. 250 mA of resistive current. C. 250 mA of capacitive current. D. 250 mA of in-phase current.
C. 250 mA of capacitive current.
If an electron has a charge of -1 unit, a hole has: A. A charge of -1 unit B. No charge C. A charge of +1 unit D. A charge that depends on the semiconductor type
C. A charge of +1 unit
Which of these diode types might be found in the oscillator circuit of a microwave radio transmitter? A. A rectifier diode B. A cat whisker C. An IMPATT diode D. None of the above
C. An IMPATT diode
Carbon-composition resistors: A. Can handle lots of power B. Have capacitance or inductance along with resistance C. Are comparatively nonreactive D. Work better for ac than for dc
C. Are comparatively nonreactive
A dynamic memory will store information: A. Even when power is not applied to the memory B. As long as power is applied to the memory C. As long as power is applied and the memory is refreshed periodically D. None of these
C. As long as power is applied and the memory is refreshed periodically
Zener voltage is also known as: A. Forward break over voltage B. Peak forward voltage C. Avalanche voltage D. Reverse bias
C. Avalanche voltage
The pulse-width of an active high clock pulse is the time the: A. Data will be held on the output after a clock signal B. Data must be held on the input after a clock edge C. Clock must be high D. Clock must be low
C. Clock must be high
"The sum of the emf's and potential differences around a closed loop equals zero" is a consequence of: A. Newton's third law B. Newton's second law C. Conservation of energy D. Conservation of charge
C. Conservation of energy
What is the meaning of the term "time constant of an RL circuit"? The time required for the: A. Current in the circuit to build up to 36.8% of the maximum value. B. Voltage in the circuit to build up to 63.2% of the maximum value. C. Current in the circuit to build up to 63.2% of the maximum value. D. Voltage in the circuit to build up to 36.8% of the maximum value
C. Current in the circuit to build up to 63.2% of the maximum value.
The purpose of doping is to: A. Make the charge carriers move faster B. Cause holes to flow C. Give a semiconductor material certain properties D. Protect devices from damage in case of transients
C. Give a semiconductor material certain properties
A three-state buffer is a device that: A. Has three different output lines B. Has three different logic levels C. Has a high impedance state in addition to normal 0 and 1 levels D. Is a special type of storage register
C. Has a high impedance state in addition to normal 0 and 1 levels
For a typical transistor, which two currents are nearly the same? A. IB and IE. B. IB and IC. C. IC and IE. D. None of the above
C. IC and IE.
In a parallel ac circuit with XL and XC, A. IL and Ic are 90 degree out of phase. B. IL and IC are in phase. C. IL and IC are 180 degree out of phase. D. XL and XC are 90 degree out of phase.
C. IL and IC are 180 degree out of phase.
What is the cause of a minimum Q on a single-tuned LC circuit? A. Decreased series resistor B. Decreased shunt resistor C. Increased shunt resistor D. Decreased capacitance
C. Increased shunt resistor
Which of the following circuits is used for production of delays? A. Astable multivibrator B. Bistable multivibrator C. Monostable multivibrator D. Schmitt-trigger
C. Monostable multivibrator
Magnetic flux can always be attributed to: A. Ferromagnetic materials B. Aligned atoms C. Motion of charged particles D. The geomagnetic field
C. Motion of charged particles
The purpose of the fetch cycle in a computer is to: A. Obtain input data B. Obtain memory data C. Obtain an instruction D. Implement a specific operation
C. Obtain an instruction
A changing magnetic field: A. Produces an electric current in an insulator. B. Magnetizes the earth. C. Produces a fluctuating electric field. D. Results from a steady electric current.
C. Produces a fluctuating electric field.
An encoder is an MSI circuit that: A. Provides for delivering one of two or more inputs to an output B. Selects a given output line based on a binary input code C. Provides an output code that corresponds to which of a set of input lines is true D. Provides a storage of a certain number of binary bits
C. Provides an output code that corresponds to which of a set of input lines is true
What is expected when two 20 k, 1 watt resistor in parallel are used instead of one 10 k, 1 watt? A. Provides higher current B. Provides less power C. Provides more power D. Provides wider tolerance
C. Provides more power
What is expected when two 20 kohms, 1 watt resistor in parallel are used instead of one 10kohms, 1 watt? A. Provides higher current B. Provides less power C. Provides more power D. Provides wider tolerance
C. Provides more power
If an emf in circuit A produces a current in circuit B, then the same emf in circuit B produces the same current in circuit A. This theorem is known as A. Maximum power transfer theorem B. Millman's theorem C. Reciprocity theorem D. Norton's theorem
C. Reciprocity theorem
A crystal set: A. Can be used to transmit radio signals B. Requires a battery with long life C. Requires no battery D. Is useful for rectifying 60-Hz ac
C. Requires no battery
What type of wave is characterized by a rise time significantly faster than the fall time (or vice versa)? A. Cosine wave. B. Square wave. C. Sawtooth wave. D. Sine wave
C. Sawtooth wave
The first person who used Boolean algebra for the design of relay switching circuits was A. Aristotle B. Boole C. Shannon D. Ramanujam
C. Shannon
In any network made up of linear resistances and containing more than one source of e.m.f., the resultant current flowing in any branch is the algebraic sum of the currents that would flow in that branch if each source was considered separately. What is this theorem? A. Thevenin's theorem B. Norton's theorem C. Superposition theorem D. Millman's theorem
C. Superposition theorem
A 100-ohm resistor, R1, and a 300-ohm resistor, R2, are in parallel across a dc voltage source. Which resistor dissipates more power? A. The 300-ohm resistor. B. Both resistors dissipate the same amount of power. C. The 100-ohm resistor. D. It cannot be determined.
C. The 100-ohm resistor.
What is the only amplifier configuration that provides both voltage and current gains? A. The common-base amplifier B. The emitter follower C. The common-emitter amplifier D. The common-collector amplifier
C. The common-emitter amplifier
Which of the following units can represent magnetic flux density? A. The volt-turn. B. The ampere-turn. C. The gauss. D. The gauss-turn.
C. The gauss.
If the reverse bias exceeds the avalanche voltage in a P-N junction: A. The junction will be destroyed B. The junction will insulate; no current will flow C. The junction will conduct current D. The capacitance will become extremely high
C. The junction will conduct current
Which of the following statements is false? A. For non-magnetic materials reluctance is high B. Energy loss due to hysteresis is greater for harder magnetic materials C. The remanence of a ferrous material is measured in ampere/meter D. Absolute permeability is measured in henrys per meter
C. The remanence of a ferrous material is measured in ampere/meter
An unimportant factor concerning the frequency at which a P-N junction will work effectively is: A. The type of semiconductor material B. The cross-sectional area of the junction C. The reverse current D. The capacitance with reverse bias
C. The reverse current
Which of the following statements is true? A. Resistors always have axial leads. B. Resistors are always made from carbon. C. There is no correlation between the physical size of a resistor and its resistance value. * D. The shell life of a resistor is about 1 year.
C. There is no correlation between the physical size of a resistor and its resistance value.
The purpose of the processing function in a system is: A. To store information that is needed later B. To generate outputs on the basis of present and past inputs C. To get information into, act on it, and output it from the system D. None of these
C. To get information into, act on it, and output it from the system
In a series RC circuit, A. Vc and VR are in phase. B. VT and I are always in phase. C. VR and I are in phase. D. VR leads I by 90 degrees
C. VR and I are in phase.
In a transistor amplifier, what happens to the collector voltage, Vc, when the collector current, Ic increases? A. Vc increase. B. Vc stays the same. C. Vc decreases. D. It cannot be determined
C. Vc decreases.
In a series RC circuit, A. Vc leads VR by 90 degrees B. Vc and I are in phase. C. Vc lags Vr by 90 degrees D. Both B and C.
C. Vc lags Vr by 90 degrees
When the frequency of the applied voltage decreases in a parallel RL circuit, A. the phase angle becomes less negative. B. ZEQ increases. C. ZEQ decreases. D. Both A and B
C. ZEQ decreases.
When the frequency of the applied voltage increases in a series RC circuit, A. the phase angle becomes more negative. B. ZT increases. C. ZT decreases. D. Both A and C.
C. ZT decreases.
Electromotive force is provided by: A. resistance's B. a conducting path C. an electric current D. an electrical supply source
C. an electric current
For getting an output from an XNOR gate, its both inputs must be A. high B. low C. at the same logic level D. at the opposite logic levels
C. at the same logic level
If a conductor is horizontal, the current flowing from left to right and the direction of the surrounding magnetic field is from above to below, the force exerted on the conductor is: A. from left to right B. from below to above C. away from the viewer D. towards the viewer
C. away from the viewer
Like a latch, the flip-flop belongs to a category of logic circuits known as A. monostable multivibrators B. astable multivibrators C. bistable multivibrators D. None of these
C. bistable multivibrators
If a circuit has an admittance of Y = 0.2 + j0.6, the circuit is A. purely inductive B. inductive C. capacitive D. reactive
C. capacitive
Above resonance, a parallel LC circuit appears A. inductive. B. resistive. C. capacitive. D. None of the above
C. capacitive.
Below resonance, a series LC circuit appears A. inductive. B. resistive. C. capacitive. D. None of the above
C. capacitive.
The power dissipation in a transistor is the product of A. emitter current and emitter to base voltage B. emitter current and collector to emitter voltage C. collector current and collector to emitter voltage D. none of the above
C. collector current and collector to emitter voltage
An inductor and a capacitor form a resonant circuit. The capacitor value is increased by four times. The resonant frequency will: A. increase by four times B. double C. decrease to half D. decrease to one quarter
C. decrease to half
If a thermistor has a negative temperature coefficient (NTC), its resistance A. increases with an increase in operating temperature. B. decreases with a decrease in operating temperature. C. decreases with an increase in operating temperature. D. is unaffected by its operating temperature.
C. decreases with an increase in operating temperature.
One precaution to observe when checking resistors with an ohmmeter is to A. check high resistance on the lowest ohms range B. check low resistance on the highest ohms range. C. disconnect all parallel paths. D. make sure your fingers are touching each test lead.
C. disconnect all parallel paths.
In a bipolar transistor which current is largest A. collector current B. base current C. emitter current D. base current or emitter current
C. emitter current
The power transferred from a supply source to a load is at its maximum when the resistance of the load is _______ the internal resistance of the source. A. lower than B. greater than C. equal to D. one-half of the
C. equal to
If a resistor in a series circuit is shorted, the series current, I, A. decreases B. stays the same. C. increases. D. drops to zero.
C. increases.
If a circuit has an admittance of Y = 0.5- j0.9, the circuit is A. resistive C. inductive B. capacitive D. reactive
C. inductive
In a series ac-circuit, if the line frequency is more than the resonant frequency, the circuit behaves as A. resistive C. inductive B. reactive D. capacitive
C. inductive
In a parallel circuit, the individual branch currents are A. not related to the branch resistance values B. directly proportional to the branch resistance values C. inversely proportional to the branch resistance values. D. None of the above
C. inversely proportional to the branch resistance values.
Boolean algebra is essential based on A. symbols C. logic B. truth D. numbers
C. logic
With the positive probe on an NPN base, an ohmmeter reading between the other transistor terminals should be: A. open B. infinite C. low resistance D. high resistance
C. low resistance
The impedance of a series LC circuit at resonance is A. maximum. B. nearly infinite. C. minimum. D. Both A and B.
C. minimum.
A higher Q for a resonant circuit provides a A. dampened response curve. B. wider bandwidth. C. narrower bandwidth. D. None of the above.
C. narrower bandwidth.
A half-adder can be constructed from A. two XNOR gates only B. one XOR and one OR gate with their outputs connected in parallel C. one XOR and one OR gate with their inputs connected in parallel D. one XOR gate and one AND gate
C. one XOR and one OR gate with their inputs connected in parallel
An n-type semiconductor is a semiconductor that has been doped with A. trivalent impurity atoms. B. impurity atoms whose electron valence is + 4. C. pentavalent impurity atoms. D. None of the above.
C. pentavalent impurity atoms
Which of the following resistors has the smallest physical size? A. wire-wound resistors. B. carbon-composition resistors. C. surface-mount resistors. D. potentiometers.
C. surface-mount resistors.
For a transistor to function as an amplifier, A. both the EB and CB junctions must be forward-biased. B. both the EB and CB junctions must be reverse-biased. C. the EB junction must be forward biased and the CB junction must be-biased. D. the CB junction must be forward biased and the EB junction must be reverse-biased.
C. the EB junction must be forward-biased and the CB junction must be-biased.
The effect of inductance occurs in an electrical circuit when: A. the resistance is changing B. the flux is changing C. the current is changing D. all of the above
C. the current is changing
Conventional current is considered A. the motion of negative charges in the opposition direction of electron flow. B. the motion of positive charges in the same direction as electron flow. C. the motion of positive charges in the opposition direction of electron flow. D. None of the above.
C. the motion of positive charges in the opposition direction of electron flow.
If one branch of a parallel circuit becomes open, A. all remaining branch currents increase. B. the voltage across the open branch will be 0 V. C. the remaining branch currents do not change in value. D. the equivalent resistance of the circuit decreases.
C. the remaining branch currents do not change in value.
What is multi-wire connection between digital circuits?
Cable ribbon
What is the most influential factor in the switching speed of saturated bipolar transistor?
Charge storage
What the most negative point of a full-wave rectifier circuit?
Chassis
What software converts a high-level language program into machine or assembly language program?
Compiler
What are the two stable operating conditions of an SCR?
Conducting and nonconducting
What law whereby the attraction or repulsion between two magnetic poles is directly proportional to their strengths?
Coulomb`s first law
What term is used to describe bias condition of a device or circuit where no current can flow?
Cut-off
Which of the following dry cells has the largest height?
D
How many degrees are there in one complete sine wave cycle? A. 90 degrees. B. 270 degrees. C. 180 degrees. D. 360 degrees.
D. 360 degrees.
What is the meaning of the term "time constant of an RC circuit"? The time required to charge the capacitor in the circuit to: A. 23.7% of the supply voltage. B. 36.8% of the supply voltage. C. 57.3% of the supply voltage. D. 63.2% of the supply voltage.
D. 63.2% of the supply voltage.
What is the description of a square wave? A. A wave with only 300 degrees in one cycle. B. A wave whose periodic function is always negative. C. A wave whose periodic function is always positive. D. A wave that abruptly changes back and forth that abruptly
D. A wave that abruptly changes back and forth that abruptly changes back and forth between two voltage levels and stays at these levels for equal amounts of time.
The digital equivalent of an electric series circuit is the _____ gate. A. NOR C. NAND B. OR D. AND
D. AND
For a capacitor in a sine-wave ac circuit, A. Vc lags ic by 90 degrees B. ic leads Vc by 90 degrees C. ic and Vc have the same frequency. D. All of the above.
D. All of the above
A 555 IC timer can be used to operate as A. a monostable multivibrator B. an astable multivibrator C. a voltage controlled oscillator D. All of these
D. All of these
A glitch is a: A. Momentary 0-to-1-to-0 signal sequence B. Momentary 1-to-0-to-1 signal sequence C. A noise pulse D. Any of the above
D. Any of the above
A dual threshold display in a logic analyzer provides information about: A. Glitch occurrences B. Rise times C. Fall times D. B and C above
D. B and C above
What will happen to a parallel ac circuit if its line frequency is more than the resonant frequency? A. Becomes purely resistive B. Becomes purely capacitive C. Becomes inductive D. Becomes capacitive
D. Becomes capacitive
Transient currents in electrical circuit are associated with A. Inductors B. Capacitors C. Resistors D. Both A and B
D. Both A and B
For a transistor operating in the active region, A. IC = Beta(dc) X IB. B. Vcc has little or no effect on the value of IC. C. IC is controlled solely by VCC. D. Both A and B.
D. Both A and B.
Removing the emitter bypass capacitor in a common-emitter amplifier will A. decrease the voltage gain, Av. B. increase the input impedance, Zin. C. increase the voltage gain, Av. D. Both A and B
D. Both A and B.
The Q of a parallel resonant circuit can be lowered by A. placing resistor in parallel with the tank. B. adding more resistance in series with the coil. C. decreasing the value of L or C D. Both A and B.
D. Both A and B.
Which of the following safety rules should be observed while working on live electric circuit? A. Keep yourself well insulated from earth ground. B. When making measurements in a live circuit place one hand behind your back or in your pocket. C. Make resistance measurements only in a live circuit. D. Both A and B.
D. Both A and B.
A diode is a A. unidirectional device. B. linear device C. nonlinear device D. Both A and
D. Both A and C
A swamping resistor in a commonemitter amplifier A. stabilizes the voltages gain. B. increases the voltage gain. C. reduces distortion. D. Both A and C.
D. Both A and C.
If one branch of a parallel circuit is short-circuited. A. the fuse in the main line will blow. B. the voltage across the shortcircuited branch will measure the full value of applied voltage. C. all the remaining branches are effectively short-circuited as well. D. Both A and C.
D. Both A and C.
When the frequency of the applied voltage increases in a parallel RC circuit, A. the phase angel increases. B. ZEQ increases. C. ZEQ decreases. D. Both A and C.
D. Both A and C.
If a neutral atom loses one of its valence electrons, it becomes a (n) A. negative ion. B. electrically charged atom. C. positive ion. D. Both B and C.
D. Both B and C.
Which of the following statements is true? A. Unlike charges repel each other. B. Like charges repel each other. C. Unlike charges attract each other. D. Both B and C.
D. Both B and C.
A dynamic memory generally contains: A. No decoders B. Row decoders C. Column decoders D. Both row and column decoders
D. Both row and column decoders
A diode audio limiter circuit: A. Is useful for voltage regulation B. Always uses Zener diodes C. Rectifies the audio to reduce distortion D. Can cause objectionable signal distortion
D. Can cause objectionable signal distortion
A diode audio limiter circuit: A. Is useful for voltage regulation B. Always uses Zener diodes C. Rectifies the audio to reduce distortion D. Can cause objectionable signal distortion
D. Can cause objectionable signal distortion
What is the ability to store energy in an electric field called? A. Inductance B. Resistance C. Tolerance D. Capacitance
D. Capacitance
Which of the following is combined with an inductor to make a tuned circuit? A. Zener diode C. Resistor B. Potentiometer D. Capacitor
D. Capacitor
The set-up time for a D-type flip-flop is the time that the: A. Data will be held on the output after a clock signal B. Data must be held on the input after a clock edge C. Clock must be high D. Data must be stable prior to a clock edge
D. Data must be stable prior to a clock edge
Halving the cross-sectional area of a conductor will: A. Not affect the resistance. B. Quarter the resistance. C. Half the resistance. D. Double the resistance.
D. Double the resistance.
Of the following, which material allows the lowest forward voltage drop in a diode? A. Selenium B. Silicon C. Copper D. Germanium
D. Germanium
What is the ability to store energy in a magnetic field called? A. Admittance B. Capacitance C. Resistance D. Inductance
D. Inductance
The processor in a computer performs: A. The function of main system memory B. Involves transfer of data only from memory to processor or back C. Provides only arithmetic or logic operations D. Is the central control element of the system
D. Is the central control element of the system
What is the significance of connecting loads in parallel? A. It makes power consumption less B. It provides greater efficiency C. It increases the safety factor D. It allows independent operations of loads
D. It allows independent operations of loads
What is the significance of connecting loads in parallel? A. It makes power consumption less B. It provides greater efficiency C. It increases the safety factor D. It allows independent operations of loads
D. It allows independent operations of loads
Characteristics of the current in a series R-L-C circuit at resonance. A. It is dc B. It is a minimum C. It is zero D. It is at maximum
D. It is at maximum
How do you compute true power (power dissipated in the circuit) in a circuit where AC voltage and current are out of phase? A. Multiply RMS voltage times RMS current. B. Subtract apparent power from the power factor. C. Divide apparent power by the power factor. D. Multiply apparent power times the power factor.
D. Multiply apparent power times the power factor.
If ac is applied to a diode, and the peak ac voltage never exceeds the avalanche voltage, then the output is: A. AC with half the frequency of the input B. AC with the same frequency as the input C. AC with twice the frequency of the input D. None of the above
D. None of the above
A NOR gate is ON only when all its inputs are A. ON C. Positive B. High D. OFF
D. OFF
What is the term for the out-of-phase power associated with inductors and capacitors? A. Effective power. B. True power. C. Peak envelope power. D. Reactive power.
D. Reactive power.
The invalid state of a NAND latch occurs when A. S=1, C=0 B. S=0, C=1 C. S=1, C=1 D. S=0, C=0
D. S=0, C=0
A significant advantage, in some situations, of a toroidal coil over a solenoid is: A. The toroid is easier to wind B. The solenoid cannot carry as much current C. The toroid is easier to tune D. The magnetic flux in a toroid is practically all within the core
D. The magnetic flux in a toroid is practically all within the core
Which of the following does not result from adding an acceptor impurity? A. The material becomes P type B. Current flows mainly in the form of holes C. Most of the carriers have positive electric charge D. The substance has an electron surplus
D. The substance has an electron surplus
A series circuit in which desired portions of the source voltage may be tapped off for use in equipment. A. Voltage selector B. Dividing network C. Voltage trap D. Voltage divider
D. Voltage divider
Avalanche voltage is routinely exceeded when a P-N junction acts as a: A. Current rectifier B. Variable resistor C. Variable capacitor D. Voltage regulator
D. Voltage regulator
Transient disturbance is produced in a circuit whenever A. it is suddenly connected or disconnected from the supply B. it is shorted C. its applied voltage is changed suddenly D. all of the above
D. all of the above
An electric bell depends for its action on: A. a permanent magnet B. reversal of current C. a hammer and a gong D. an electromagnet
D. an electromagnet
Which of the following statements is false? The inductance of an inductor increases: A. with a short, thick coil B. when wound on an iron core C. as the number of turns increases D. as the cross-sectional area of the coil decreases
D. as the cross-sectional area of the coil decreases
If an ac-series circuit is supplied with a source whose frequency is less than that of fr, the circuit becomes A. resistive B. reactive C. inductive D. capacitive
D. capacitive
The purpose of a clock input to a flip-flop is to A. clear the device B. set the device C. always cause the output to change the states D. cause the output to assume a state dependent on the controlling inputs
D. cause the output to assume a state dependent on the controlling inputs
To operate properly, a transistor's base-emitter junction must be forward biased with reverse bias applied to which junction? A. collector-emitter B. base-collector C. base-emitter D. collector-base
D. collector-base
If the diameter of a wire is doubled, its current carrying capacity becomes A. one-fourth B. half C. twice D. four times
D. four times
The primary function of the bias circuit is to A. hold the circuit stable at VCC B. hold the circuit stable at Vin C. ensure proper gain is achieved D. hold the circuit stable at the designed Q-point
D. hold the circuit stable at the designed Q-point
At room temperature the current in an intrinsic semiconductor is due to A. holes B. electrons C. ions D. holes and electron
D. holes and electrons
In a p-type semiconductor, the majority current carriers are A. free electrons. B. valence electrons. C. protons. D. holes.
D. holes.
In an n-type semiconductor, the minority current carriers are A. free electrons. B. protons. C. valence electrons. D. holes.
D. holes.
The best place to use a wirewound resistor is _____. A. in a radio-frequency amplifier B. when the resistor doesn't dissipate much power C. in a high-power, radio frequency circuit D. in a high-power, direct-current circuit
D. in a high-power, direct-current circuit
What is the biggest disadvantage of the common-base amplifier? A. its high input impedance. B. its low voltage gain. C. its high output impedance. D. its low input impedance.
D. its low input impedance.
The current at resonance in a series LC circuit is A. zero. B. minimum. C. different in each component. D. maximum
D. maximum.
Which of the following axial-lead resistor types usually has a blue, light green or red body? A. wire-wound resistors. B. carbon-composition resistors. C. carbon-film resistors. D. metal-film resistors.
D. metal-film resistors.
A wire with a smaller cross-sectional area will produce: A. less heat B. more conductance C. less resistance D. more heat
D. more heat
The most obvious identifying feature of a TTL gate is its A. large fan-out B. high power dissipation C. interconnected transistors D. multiemitter transistor
D. multiemitter transistor
A network contains linear resistors and ideal voltage sources. If values of all the resistors are doubled, then the voltage across each resistor is A. increase by 4 times B. half C doubled D. no change
D. no change
While obtaining minimal sum of product expression, A. all don't cares are ignore B. all don't cares are treated as logic 1s C. all don't cares are treated as logic 0s D. only such don't cares that aid minimization are treated as logic 1s
D. only such don't cares that aid minimization are treated as logic 1s
To double the resonant frequency of an LC circuit with a fixed value of L, the capacitance, C, must be A. doubled. B. quadrupled. C. reduced by one-half. D. reduced by one-quarter.
D. reduced by one-quarter.
Double-energy transients are produced in circuits consisting of A. two or more resistors B. resistance and inductance C. resistance and capacitance D. resistance, inductance and capacitance
D. resistance, inductance and capacitance
On the schematic symbol of a pnp transistor, A. the arrow points out on the emitter lead. B. the arrow points out on the collector lead. C. the arrow points in on the base lead. D. the arrow points in on the emitter lead.
D. the arrow points in on the emitter lead.
Which transistor region is very thin and lightly doped? A. the emitter region. B. the collector region. C. the anode region. D. the base region.
D. the base region
A bipolar junction transistor has A. only one p-n junction. B. three p-n junctions. C. no p-n junctions. D. two p-n junctions.
D. two p-n junctions.
A resistor with a power rating of 25 W is most likely a A. carbon-composition resistor. B. metal-film resistor. C. surface-mount resistor. D. wire-wound resistor.
D. wire-wound resistor.
Which is not a part of CRT of oscilloscope?
Digital Panel Meter
What refers to the of dc motor-generator with common field coils for both motor and generator?
Dyna Motor
What current flows in the core of a transformer that produces heat?
Eddy current
What do you call the emission of electrons from hot bodies?
Edison effect
What is known as the reciprocal of capacitance?
Elastance
What is a relaxation oscillator that does not require any form of external excitation?
Free running
Which semiconductor material is commonly used in the construction of LED?
GaAs
Which is not a part of a magnetron oscillator?
Grid
When a small voltage is generated across the width of a conductor carrying current in an external magnetic field, the effect is called the ____ effect.
Hall
What concept whereby a small voltage is generated by a conductor with current in an external magnetic field?
Hall effect
What is the effect in terms of bandwidth when the Q of a single-tuned stage is doubled?
Halved
What do you call the oscillator circuit that uses a tapped coil tuned circuit?
Hartley
How does an ohmmeter behave if its positive lead is connected to cathode of a diode while negative to anode?
Has infinite high resistance
What T-section has capacitance only in the series arms and inductance only in the parallel branch?
High-pass filter
A SAW device has electrodes that are described as __________.
Interdigital
Logic family below is noted for low power consumption?
I²L
What oscillator operates on the principle of velocity modulation and changing speed of electron passing through the tube?
Klystron
What device stays on once triggered and stores one of the two conditions as a digital circuit?
Latch
What is the program used to enter a program into the computer memory?
Loader
What T-section has inductance only in the series arms and capacitance only in the parallel branch?
Low-pass filter
What is an instruction in a source language that is to be replaced by a defined sequence of instruction in the same source language?
Macro-instruction
What type of overload operates on the principle of electromagnetism?
Magnetic
Which of the following refers to the point where the intensity of magnetic line of force is maximum?
Magnetic pole
What do you call the condition under which there is no power loss due to reflection at a source/load junction owing to the fact that the load impedance is conjugate of the source impedance?
Maximum power transfer
Which is called the electrical prime mover?
Motor
A solid-state logical device which only gives a "1" output if all inputs are "0" is called a ______ gate.
NOR
How do you call an eight-element vacuum-tube?
Octode
What gaseous tube uses a pool of liquid mercury as its cathode?
Phanotron
Classified as a hot-carrier type diode and uses a metal catwhisker as its anode.
Point-contact
What user program has the ability to move a robot axis to any position within its range?
Point-to-point
What do you call the term in electronic measuring devices when a metal increases resistance due to heat produced by current flowing through them?
Positive temperature coefficient
What is a sequence of instruction that tells the computer machine on how available data shall be processed?
Program
Speed of a logic circuit is normally expressed as:
Propagation delay
What power is found by multiplying the sine of the phase angle, the effective source voltage and the effective source current?
Reactive Power
What is the cause of parallax error in analog-type meter?
Reading the meter at an angle
What is defined as the ratio of required input signal to the amount of deflection?
Sensitivity
What is the maximum rate at which the output voltage can change in a given op-amplifier?
Slew Rate
What emf is induced when a conductor is stationary and the magnetic field is moving or changing?
Statically induced emf
What is a thin layer in a PCB which is firmly bounded to an insulating base material?
Substrate
What is the most widely used digital logic family?
TTL
What is the name of the field-effect transistor designed to work as a power amplifier?
VFET
Which of the following Integrated Circuits contains the most gate?
VLSI
Which meter uses a dual triode tube and requires external power for operation?
VTVM (Vacuum Tube Voltmeter)
What electronic component is a non-linear resistor and its resistance is a function of the voltage cross it?
Varistor
When a piezoelectric crystal is mechanically deformed:
Voltages are produced.
For an accurate resistance measurement, ______ is used.
Wheatstone bridge
What law states that the ratio of the thermal conductivity to the electric conductivity is proportional to the absolute temperature for all metals?
Wiedemann-Franz`s law
Signal generators are classified according to frequency which are either AF or RF generators, AF generators are referred to as:
audio generators
An electron travels due north through a vacuum in a region of uniform magnetic field that is also directed due north. It will:
be unaffected by the field
The unit for the density of data recorded on magnetic tape is measure in:
bits per inch
Comparing a vacuum tube diode and a germanium diode, the latter:
cannot be used with as high PIV
Lines of the magnetic field produced by a long straight wire carrying a current are:
circles that are concentric with the wire
In a series RLC circuit, V_L = V_C when the:
circuit is at resonance
The circulating or fly-wheel current in a tank circuit recreates the sinusoidal voltage waveform in:
class C RF power amplifiers
The figure below shows a rectangular coil of wire placed in a magnetic field and free to rotate about axis AB. If the current flows into the coil at C, the coil will:
commence to rotate clockwise
Using BJT, _________ is the amplifier configuration which has the highest gain.
common emitter
Another name for a magnetic starter is a
contactor
The response of the filter is plotted in ______ in a bode plot.
decibel
When you demagnetized properly by applying an AC field and then gradually reduced it to zero, it is called _______.
degaussing
Materials with permeabilities slightly less than that of free space are referred to as
diamagnetic
Parallel cells have the same voltages as one cell but have:
different current capacity
The processing of a number sequence is the method used in __________.
digital filters
When an impurity having five electrons in the outer shell is added to the intrinsic semiconductor, it is called a/an
donor
Choose the correct statement concerning electric field lines:
field lines are close together where the field is large
In a diode, when the cathode is negative with respect to the cathode, diode is said to be:
forward bias
Diac is another term for a:
four-layer diode
Crystals have very:
high quality factor
The arrow in the symbol of a transistor indicates the direction of:
hole current in the emitter
A power in a circuit that is not lost in the form of heat is called ______.
imaginary power
The magnetic dipole moment of a current-carrying loop of wire is in the positive z direction. If a uniform magnetic field is in the positive x direction the magnetic torque on the loop is:
in the positive y direction
For loop of a current-carrying wire in a uniform magnetic field the potential energy is a minimum if the magnetic dipole moment of the loop is:
in the same direction as the field
Positive feedback:
increases gain and distortion.
A triac in _______ is equivalent to two SCRs.
inverse parallel
The ratio between primary and secondary current is a transformer does not depend on the:
nature of the core
An electron moves in the negative x direction, through a uniform magnetic field in the negative y direction. The magnetic force on the electric is in the ______.
negative z direction
When a logic circuit rejects an unwanted signal, this is termed as ________.
noise margin
Two long parallel straight wires carry equal currents in opposite directions. At a point midway between the wires, the magnetic field they produce is:
non-zero and perpendicular to the plane of the two wires
An over tone quartz crystal is purposely ground to oscillate on:
odd or even harmonics of the fundamental frequency.
The direction of the magnetic field in a certain region of space is determined by firing a test charge into the region with its velocity in various directions in different trials. The field direction is:
one of the directions of the velocity when the magnetic force is zero
A bar magnet is moved at a steady speed of 1.0 m/s towards a coil of wire which is connected to a center-zero galvanometer. The magnet is now withdrawn along the same path of 0.5 m/s. The deflection of the galvanometer is in the:
opposite direction as previously, with the magnitude of the deflection halved
Erratic operation can be isolated by:
piggybacking IC
The anode of a semiconductor diode indicates a ______ charge during conduction.
positive
The current is from left to right in the conductor shown. The magnetic field is into the page and point S is at a higher potential than point T. The charge carriers are _____.
positive
One disadvantage of a dynamic RAM is a result of the need for:
refreshing
A constant current is sent through a helical coil. The coil:
tends to get shorter
A "coulomb" is:
the amount of charge that flows past a point in one second when the current is 1 A
In the symbol for the pnp transistor:
the arrow points towards the base
The magnetic field B inside a long ideal solenoid is independent of:
the cross-sectional area of the solenoid
An electric field is most directly related to:
the force acting on a test charge
The figure shows the motion of electrons in a wire that is near the N pole of a magnet. The wire will be pushed:
upwards
For a zener diode, the breakdown voltage is __________.
very sharp
Resistor noise is classified as ______ noise.
white
An electron is moving north in a region where the magnetic field is south. The magnetic force exerted on the electron is _____.
zero