Industrial Electronics Maintenance

DC power output of half wave rectifier is equal to ____________

• 2(Im)2π2frac{2left(I_mright)^2}{pi^2}π22(Im​)2​
• (Im)22π2RLfrac{left(I_mright)^2}{2pi^2}R_L2π2(Im​)2​RL​
• (Im)2π2RLfrac{left(I_mright)^2}{pi^2}R_Lπ2(Im​)2​RL​
• 4(Im)2π2RLfrac{4left(I_mright)^2}{pi^2}R_Lπ24(Im​)2​RL​

In a PUT, the cathode can be biased to a desired voltage with an external voltage divider, so that when the anode voltage exceeds this “programmed” level, the PUT turns on.

• True
• False

The application of external voltage across the two terminals.

• Bias

One application of UJT is it can amplify signal similar to conventional BJTs and FETs.

• True
• False

Given the circuit above, determine the value of Vo. Assume that GaAs has a potential barrier of 1.2V.

• 9.3V

The state of an ideal diode in the region of non conduction is ________

• An open circuit
• A short circuit
• Unpredictable
• Undefined

The number 1000 would appear just immediately after

• FFFF (hex)
• 1111 (binary)
• 7777 (octal)
• All of the above

What type of electron emission is employed on vacuum tubes?

• field emission
• thermionic emission
• secondary emission
• photoelectric emission

When a PN junction is connected to any external bias, it is considered in thermal equilibrium condition.

• True
• False

Majority Carrier in a P-type Semiconductor.

• Acceptor Ion
• Donor Ion
• Positive Charge
• Negative Charge

A hexadecimal odometer displays F 52 F. The next reading will be

• F52E
• G52F
• F53F
• F53O

It is the main processing unit for an on board maintenance system.

• CMC
• OMS
• BITE

Choose 1 subsystem of Onboard Maintenance System

Who among in 1959 from Texas Instruments developed the first integrated circuits?

• J.A. Fleming
• Jack Kilby
• Lee De Forest
• Shockly

Among the logic families, the family which can be used at very high frequency greater than 100 MHz in a 4 bitsynchronous counter is

• TTLAS
• CMOS
• ECL
• TTLLS

Which of the following gate is a two-level logic gate

• OR gate
• NAND gate
• EXCLUSIVE OR gate
• NOT gate.

A career in electronics where he works in one or more areas of power-generating equipment, power-transmitting equipment, electric motors, machinery control, and lighting and wiring installation.

• electrical engineer
• electrician
• computer engineer
• computer technician

A semiconductor doped with a pentavalent impurity element which has five electrons in its valence shell.

The motion of electrons through a _______ gives us electric current.

• conductor

Most of the digital computers do not have floating point hardware because

• floating point hardware is costly
• it is slower than software
• It is not possible to perform floating point addition by hardware
• Of no specific reason

The datasheet of a certain UJT with a silicon diode gives an intrinsic standoff ratio of 0.5, determine the peak point emitter voltage if the supply is 15V.

• 6.8Volts

Which of the following elements doesn't belong to the group?

• As
• P
• Sb
• Al

A reverse-biased silicon diode has about 0.7 V across it

• True
• False

The forward voltage drop across a germanium diode is _____.

• 0.3 V

Determine the supply voltage for a silicon PUT if it is determined that η = 0.5, Peak Voltage= 12.3 V. (use the correct unit)

• 23.2V

-The word electronics is derived from ______ mechanics, which means to study the behavior of an electron under different conditions of applied electric field.

• electron

Being a learner in Electronics 10, which of the seven career in Electronics you will choose? Explain in 3 to 5 sentence paragraph.

CMC stands for?

• Central Maintenance Computer
• Central Maintenance Center
• Center Maintenance Computer

Diode vacuum tube was the first electronic component invented by _________

• J.A. Fleming

It is installed in many systems throughout the aircraft including navigation systems, flight control systems, environmental control systems, and others.

• BITE
• CMC
• OMS

Frequency of oscillation of the device is equal to the reciprocal of the total period in _____________.

• the whole duration of operation
• one cycle
• one positive half cycle
• one negative half cycle

Pick out the CORRECT statement:

• In a positional number system, each symbol represents the same value irrespective of its position
• The highest symbol in a position number system as a value equal to the number of symbols in the system
• It is not always possible to find the exact binary
• Each hexadecimal digit can be represented as a sequence of three binary symbols.

Which in the career in electronics where he/she is responsible to installs, maintains, and repairs computer equipment and systems?

• automotive mechanic
• computer engineer
• automation mechanic
• computer technician

The width of the depletion layer in a PN junction in forward bias condition _______________

• Decreases
• Increases
• Remains the same
• No depletion region

NAND. gates are preferred over others because these

• Have lower fabrication area
• Can be used to make any gate
• Consume least electronic power
• Provide maximum density in a chip

In the energy band phenomenon, with the increase in temperature, the resistivity of the material _______ and the conductivity ___________.

• Increases, Increases
• Decreases, Increases
• Increases, Decreases
• Decreases, Decreases

Why do we add impurities on semiconductor materials?

• to make the manufacturing easier
• to strengthen its structure
• to improve its electrical properties
• to cut the costs of production

In a semiconductor, the conduction of current is due to _______

• Only Holes
• Only Free Electrons
• Holes and Free Electrons
• None of the above

Which of the following does not belong to the group.

• Zero Bias
• Forward Bias
• Reverse Bias
• Neutral Bias

In a silicon bilateral switch, gate terminal can be used to turn off the device.

• True
• False

The silicon bilateral switch has the ability to provide positive and negative cycles.

• True
• False

Defined as a type of extrinsic semiconductor doped with a trivalent impurity element which has three electrons in its valence shell.

• P-type Semiconductor
• N-type Semiconductor
• Intrinsic Semiconductor
• Extrinsic Semiconductor

If the arrow of crystal diode symbol is positive with respect to the bar, the the diode is in what condition?

• No Bias
• Forward Bias
• Reverse Bias
• None of the above

What is formed when an n-type and a p-type semiconductor are fused together?

• p-n junction
• ion barrier
• covalent bond
• electron flow

Electronics is the branch of physics and technology concerned with the design of circuits using _____and microchips, and with the behavior and movement of electrons in a semiconductor, conductor, vacuum, or gas.

• transistors

These are a special class of elements having a conductivity between that of a good conductor and that of an insulator.

• Capacitors
• Conductors
• Insulators
• Semiconductors

These are materials that are bad conductors of current and not allow the flow of current through them as they do not have current carrying capacity.

• Capacitors
• Conductors
• Insulators
• Semiconductors

The binary code of (21.125)10 is

• 10101.001
• 10100.001
• 10101.010
• 10100.111

Avalanche breakdown is a condition in which a diode __________.

• is subjected to a large reverse voltage
• is reverse-biased and there is a small leakage current
• has no current flowing at all
• is heated up by large amounts of current in the forward direction

What type of impurities produce n-type semiconductor?

• acceptor atoms
• trivalent impurities
• extrinsic semiconductor
• donor atoms

These are materials that have excellent current carrying capacity.

• Semiconductor
• Conductors
• Insulators
• Diodes

Determine RB1 (in ohms) for a silicon PUT if it is determined that η = 0.5, Peak Voltage= 12.3 V and RB2= 1k ohms. (type in the value of the correct answer ONLY)

• 1k

A zener diode has ______ pn junction/s.

• One
• Two
• Three
• None

An AND gate will function as OR if

• All the inputs to the gates are “1”
• All the inputs are ‘0’
• Either of the inputs is “1”
• All the inputs and outputs are complemented

For an ideal UJT, the emitter firing potential is equivalent to the intrinsic stand-off ratio multiplied by the supply voltage.

• True
• False

What is the lightest subatomic particle?

• neutron
• nucleus
• proton
• electron

Positive logic in a logic circuit is one in which

• Logic 0 and 1 are represented by 0 and positive voltage respectively
• Logic 0 and, -1 are represented by negative and positive voltages respectively
• Logic 0 voltage level is higher than logic 1 voltage level
• logic 0 voltage level is lower than logic 1 voltage level

Determine the dc load voltage in the given circuit. Assume the circuit to be ideal.

• 10.8V

Determine Vo1 and Vo2 in the given circuit.

• 0V

Calculate the power dissipation of a diode having ID = 40 mA.

• 0.028 W

If a diode is forward biased,

• its state is automatically on
• its state is automatically off
• its state depends on the bias voltage
• its state depends on its diode type

According to Shockley's equation, how can we determine the thermal voltage?

• the product of Boltzmann's constant and absolute temperature divided by the magnitude of electronic charge
• the sum of Boltzmann's constant and absolute temperature divided by the magnitude of electronic charge
• the sum of Boltzmann's constant and absolute temperature multiplied by the magnitude of electronic charge
• the difference of Boltzmann's constant and absolute temperature divided by the magnitude of electronic charge

In case of OR gate, no matter what the number of inputs, a

• 1 at any input causes the output to be at logic 1
• 1 at any input causes the output to be at logic 0
• 0 any input causes the output to be at logic 0
• 0 at any input causes the output to be at logic 1

Determine the peak load voltage of the circuit. Assume that the circuit is not ideal.

• 33.3 V

These are semiconductors in which intentionally impurities are added to make the element conductive.

These are materials that have a conductivity between a good conductor and an insulator.

• Semiconductor
• Conductors
• Insulators
• Diodes

Subject code for Aircraft Maintenance Computer System?

• AMT11A-09
• AMT11A-04
• AMT04A-11
• AMT09A-11

Common rating of Silicon Unilateral Switch and Silicon Bilateral Switch

• 0.3 V
• 0.7 V
• 5 V
• 8 V

The fan put of a 7400 NAND gate is

• 2TTL
• 5TTL
• 8TTL
• 10TTL

When a pure semiconductor is heated, what happens to its resistance?

• Goes down
• Goes up
• Remains the same
• Becomes zero

In a reverse bias condition, the depletion region offers more resistance to these majority carriers.

• True
• False

OMS stands for?

• Onboard Maintenance System

You have an unknown type of diode in a circuit. You measure the voltage across it and find it to be 0.3 V. The diode might be?

• A silicon diode
• A germanium diode
• A forward biased silicon diode
• A forward biased germanium diode

Positive Temperature Coefficient means

• resistance increase as temperature decreases
• conductance increases as temperature increases
• resistance decreases as temperature increases
• conductance decreases as temperature temperature increases

In which of the following base systems is 123 not a valid number?

• Base 10
• Base 16
• Base8
• Base 3

Which of the following electronic components was invented by Shockley, Bardeen and Brattain?

• transistor
• resistor
• capacitor
• vacuum tubes

Which is the determining factor for triggering of SUS and SBS?

• Anode gate
• Cathode Gate
• Silicon Diode
• Zener Diode

The device which controls the flow of electrons is called _______ device. These devices are the main building blocks of electronic circuits.

• electronic

The purpose of adding impurity in the semiconductor crystal is to increase the number of free electrons or holes to make it __________

• Conducive
• Stronger
• Increasing
• Conductive

How old am I? (type number only)

• 30

In PUT, the term programmable is applied because RBB, η, and VP as defined for the UJT can be controlled through the internal resistors RB1, RB2, and the supply voltage VBB.

• True
• False

A NAND gate is called a universal logic element because

• it is used by everybody
• Any logic function can be realized by NAND gates alone
• All the minization techniques are applicable for optimum NAND gate realization
• Many digital computers use NAND gates

Semiconductors in which intentionally impurities are added for making it conductive.

For a UJT, RB1 may vary from 5kΩ down to 50Ω for a corresponding change of IE from 50 mA to 0 mA.

• True
• False

UJT has a unique characteristics that when it is triggered, the emitter current increases regeneratively until it is limited by emitter power supply.

• True
• False

What is formed when a dielectric is placed between two parallel conductors?

• capacitance
• resistance
• conductance
• electromotive force

The main advantage of UJT is that it offers negative resistance characteristics.

• True
• False

A low power, low current device.

• Silicon Controlled Rectifier
• Silicon Controlled Switch
• Silicon Unilateral Switch
• All of the above

Digital computers are more widely used as compared to analog computers, because they are

• Less expensive
• Always more accurate and faster
• Useful over wider ranges of problem types
• Easier to maintain

DC average current of a half wave rectifier output is ___________

• 2Imπfrac{2I_m}{pi}π2Im​​
• Imπfrac{I_m}{pi}πIm​​
• Im2πfrac{I_m}{2pi}2πIm​​
• 1.414 Imπfrac{1.414 I_m}{pi}π1.414 Im​​

A career in electronics where he maintains controllers, assembly equipment, copying machines, robots, and other automated or computerized devices.

• computer engineer
• automotive mechanic
• automation mechanic
• computer technician

Mobile phone chargers are used to charge phone batteries by plugging it to AC power outlets. What type of semiconductor application is employed in the process?

• image projection
• amplification
• rectification
• oscillation

What do you call for the gaps left behind by electrons as they are liberated from their respected orbits?

• anion
• holes
• depletion layer
• cation

According to this law, the sum of voltages on a closed loop is equal to zero.

• Ohm's Law
• Kirchhoff's Current Law
• Kirchhoff's Voltage Law
• Maxwell's Mesh Current Analysis

BITE stands for?

• Built In Test Equipment
• Built In Text Equipment
• Build In Text Equipment

Describe the different advantages of electronics.

One application of a half wave rectifier is __________

• it converts the DC signal to AC signal
• it converts AC signal to pulsating DC signal
• used as a switch
• it amplifies

Which of the following offers good temperature stability?

• SCR
• SUS
• SBS
• All of the above

These type of semiconductors are in their purest form by nature of their existence.

• Intrinsic Semiconductors
• Extrinsic Semiconductors
• P-type Semiconductors
• N-type Semiconductors

Defined as a type of extrinsic semiconductor doped with a pentavalent impurity element which has five electrons in its valence shell.

• P-type Semiconductor
• N-type Semiconductor
• Intrinsic Semiconductor
• Extrinsic Semiconductor

A 5:1 transformer is connected to a half wave rectifier circuit with a 50k ohms load. Compute for the DC current if the input peak voltage is 220V.

• 280.11 microAmpere

A diode conducts current under normal conditions when it is _________

• Reverse biased
• Forward biased
• Avalanched
• Saturated

Which of the following is required in determining the charging period of a unijunction transistor?

• Resistor connected to supply, Capacitor, Supply Voltage, Valley and Peak Voltage Values
• Resistors connected to supply and emitter, Capacitor, Supply Voltage, Valley and Peak Voltage Values
• Internal Resistance, Resistor connected to emitter, Valley Voltage and Peak Voltage Values
• Supply Voltage and Intrinsic Stand-off Ratio

In a forward bias condition, further increase in the external applied voltage will increase the size of the depletion region.

• True
• False

These are materials that have excellent current carrying capacity or allow good flow of current through them.

• Capacitors
• Conductors
• Insulators
• Semiconductors

Addition of pentavalent impurity to a semiconductor creates _____.

• Free Electrons
• Holes
• Valence Electrons
• Valence Ion

Outputs from the CMC are provided in the form of?

The most commonly used semiconductor is _______

• GaAs
• Si
• Ge
• K

Determine the current (I) in the given circuit.

• 0 ma

An OR gate has 6 inputs. The number of input words in its truth table are

• 6
• 32
• 64
• 128

Assuming 8 bits for data, 1 bit for parity, I start bit and 2 stop bits, the number of characters that 1200 BPS communication line can transmit is

• 10 CPS
• 120 CPS
• 12CPS
• None of the above

Which of the following does not belong to the group?

• Zero Biased
• Reverse Biased
• Forward Biased
• Avalanche Biased

Give at least 5 various branches in electronics.

The efficiency of a half-wave rectifier is _______

• Low
• High
• Average
• Zero

Examples of Semiconductor.

Interbase resistance of a UJT is the resistance between emitter and pn junction when the emitter current is zero.

• True
• False

The structure of UJT is very much similar to an N-channel JFET.

• True
• False

The current in a reverse biased PN junction ______

• increases
• decreases
• equal to 0
• none of the above

In the energy band phenomenon, at absolute zero temperature, the conduction band is ____________.

• Completely filled
• Completely empty
• Halfway filled
• Halfway empty

Why Si diodes are more preferred in the manufacture of semiconductor devices?

• it is more abundant
• it has lower peak inverse voltage
• it has higher electron mobility
• all of the above

System that provide links to the applicable electronic maintenance documentation.

• CMS
• DLCS
• ACMS

NSS stands for?

• Network Server System

A half-wave rectifier is used to supply 50V d.c. to a resistive load of 800 Ω. The diode has a resistance of 25 Ω. Calculate a.c. voltage required.

• 161.99 V

Storage of 1 KB means the following number of bytes

• 1000
• 964
• 1024
• 1064

UJT in terms of junction's location is not symmetrical.

• True
• False

It is the process by which an impurity is added to a semiconductor.

• Mixing
• Doping
• Adding
• Filling

Determine the current in the given circuit.

• 3.96mA

Equivalent Circuit of a Unijunction Transistor

• Diode, one fixed resistor, one variable transistor
• Diode, Two resistors (one fixed, one variable)
• Base, Emitter, Collector
• Anode, Cathode, Gate

The number of Boolean functions that can be generated by n variables is equal to

• 2n
• 22 n
• 2n-1
• — 2n

Potential barrier of a Silicon.

• 0.1 V
• 0.3 V
• 0.7 V
• .10 V

The information from BITE are sent to the?

• CMC
• OMS
• DLCS
• ACMS

Once Programmable Unijunction Transistor is in the on state, the removal of gate voltage will turn the device off.

• True
• False

A debouncing circuit is

• An astable MV
• A bistable MV
• A latch
• A monostable MV.

Excess-3 code is known as

• Weighted code
• Cyclic redundancy code
• Self-complementing code
• Algebraic code

What is the resistor value of an ideal diode in the region of conduction?

• 0 ohms
• 1K ohms
• 5K ohms
• Infinity

A silicon diode displays a forward voltage of .25V at 10mA current at 300 Kelvin. Find the reverse saturation current. (in micro Ampere) *no need to include the unit. 3 decimal places only.

• 0.637

Which of the following is not a three terminal device?

• Silicon Unilateral Switch
• Silicon Bilateral Switch
• Shockley Diode
• Unijunction Transistor

These are materials that have no current carrying capacity.

• Semiconductor
• Conductors
• Insulators
• Diodes

The main function of this additional electrode is to prevent electrons from bouncing back to the plate and to lessen the occurrence of secondary emission.

• control grid
• suppressor grid
• screen grid
• anode

A UJT is operated with gate junction forward- biased while the JFET is normally operated with the emitter junction reverse-biased.

• True
• False

What is the ambient room temperature for electronic devices?

• 280 K
• 290 K
• 300 K
• 310 K

In the energy band phenomenon, at absolute zero temperature, the valence band is ____________.

• Completely filled
• Completely empty
• Halfway filled
• Halfway empty

The ripple factor of a half wave rectifier is ______

• 1.414
• 1.21
• .707
• .303

Which of the following is not true about semiconductors?

• resistance increases as their temperature decreases
• possesses qualities that of a conductor and insulator
• conductance increases as their temperature increases
• have less than four valence electrons

It is the maximum amount of voltage the diode can withstand in reverse bias mode on a continual basis.

• maximum repetitive reverse voltage
• maximum forward voltage
• maximum dc reverse voltage
• maximum total dissipation

An electronic system used to facilitate the maintenance of modern aircraft.

• OMS
• CMS
• BITE

(10101)2 is

• (37)10
• ( 69)10
• (41 )10
• — (5)10

In a forward bias condition, when the applied voltage is more than the potential barrier of this PN junction the resistance that is offered by the depletion region negligible.

• True
• False

Consider the representation of six-bit numbers by two’s complement, one’s complement, or by sign and magnitude: In which representation is there overflow from the addition of the integers 011000 and 011000?

• Two’s complement only
• Sign and magnitude and one’s complement only
• Two’s complement and one’s complement only
• All three representations

What happens when a p-n junction is forward biased?

• a depletion region is formed
• ions start to build up at the p-n junction
• current starts to flow
• electrons and holes disperse away from each other

Diode that is always connected in reverse bias condition.

• Zener

What is the octal equivalent of the binary number:10111101

• 675
• 275
• 572
• 573

Indicate which of the following three binary additions are correct?1.1011 + 1010 = 10101II. 1010 + 1101 = 10111III. 1010 + 1101 = 11111

• I and II
• II and III
• III only