2A672 Volume 1 Ure Questions

Approved & Edited by ProProfs Editorial Team

The editorial team at ProProfs Quizzes consists of a select group of subject experts, trivia writers, and quiz masters who have authored over 10,000 quizzes taken by more than 100 million users. This team includes our in-house seasoned quiz moderators and subject matter experts. Our editorial experts, spread across the world, are rigorously trained using our comprehensive guidelines to ensure that you receive the highest quality quizzes.

Learn about Our Editorial Process

| By Cocoanut

Cocoanut

Community Contributor

Quizzes Created: 2 | Total Attempts: 5,055

Questions: 84 | Attempts: 2,387 | Updated: Mar 20, 2023

Questions

Settings

Feedback

During the Quiz End of Quiz

Play as

Quiz Flashcard

Create your own Quiz

Unit Review Questions from CDC 2A672 Volume 1

Questions and Answers

1.

What is the simplest form of matter?
- A.
  
  Element
- B.
  
  Mixture
- C.
  
  Electrons
- D.
  
  Compound
Correct Answer
A. Element

Explanation
An element is the simplest form of matter because it consists of only one type of atom. Atoms are the basic building blocks of matter, and elements are made up of identical atoms. They cannot be broken down into simpler substances by chemical means. In contrast, mixtures are composed of two or more different substances, compounds are made up of two or more different elements chemically combined, and electrons are subatomic particles that are part of atoms.

Rate this question:
2.

In an atom, what electrons contain the most energy?
- A.
  
  The energy is shared equally by all electrons
- B.
  
  Orbiting electrons
- C.
  
  Valence electrons
- D.
  
  K shell electrons
Correct Answer
C. Valence electrons

Explanation
Valence electrons are the electrons located in the outermost energy level of an atom. These electrons have the highest energy because they are farthest away from the positively charged nucleus and experience less attraction. As a result, valence electrons are more easily involved in chemical reactions and can be transferred or shared with other atoms to form chemical bonds.

Rate this question:
3.

Atoms having more than four electrons, but less than eight are known as
- A.
  
  Insulators
- B.
  
  Conductors
- C.
  
  Stable atoms
- D.
  
  Semiconductors
Correct Answer
A. Insulators

Explanation
Atoms having more than four electrons, but less than eight are known as insulators because insulators are materials that do not easily conduct electricity. These atoms have a partially filled valence shell, which makes it difficult for them to gain or lose electrons and form stable bonds with other atoms. As a result, they do not readily conduct electricity and are poor conductors of heat.

Rate this question:
4.

The electrostatic fields around a positive ion move
- A.
  
  Inward
- B.
  
  Outward
- C.
  
  Inward, then outward
- D.
  
  Outward, then inward
Correct Answer
B. Outward

Explanation
The electrostatic fields around a positive ion move outward. This is because positive ions have a deficiency of electrons, resulting in an excess of positive charge. As a result, the electrostatic fields emanating from the positive ion repel other positive charges and attract negative charges. This repulsion causes the fields to extend outward from the ion, creating a region of influence where other charges are affected. Therefore, the correct answer is outward.

Rate this question:
5.

What are factors that affect the resistance of a material?
- A.
  
  Area, weight, and state of material
- B.
  
  Area, temperature, and type of material
- C.
  
  Temperature, weight, and state of material
- D.
  
  Temperature, type of material, and state of material
Correct Answer
B. Area, temperature, and type of material

Explanation
The factors that affect the resistance of a material are the area of the material, the temperature at which it is being used, and the type of material itself. The area of the material affects resistance because a larger area allows for more current to flow, resulting in lower resistance. Temperature affects resistance because as temperature increases, the atoms in the material vibrate more, causing more collisions with electrons and increasing resistance. The type of material also affects resistance because different materials have different atomic structures and electron configurations, which can impact the ease of electron flow and therefore resistance.

Rate this question:
6.

What is the resistance in a circuit if the power rating is 40 watts and total current is 2 amps?
- A.
  
  40 ohms
- B.
  
  20 ohms
- C.
  
  10 ohms
- D.
  
  0.5 ohms
Correct Answer
C. 10 ohms

Explanation
40/2^2 = 40/4 = 10 ohms

Rate this question:
7.

Convert 500 milliamps to standard amperage.
- A.
  
  .005 amps
- B.
  
  .05 amps
- C.
  
  .5 amps
- D.
  
  50 amps
Correct Answer
C. .5 amps

Explanation
To convert milliamps to standard amperage, you need to divide the value in milliamps by 1000. In this case, 500 milliamps divided by 1000 equals 0.5 amps. Therefore, the correct answer is 0.5 amps.

Rate this question:
8.

In a series-parallel circuit, find RT if series resistor R1 = 7 ohms, and parallel resistors R2 and R3 = 8 ohms.
- A.
  
  23 ohms
- B.
  
  15 ohms
- C.
  
  11 ohms
- D.
  
  8 ohms
Correct Answer
C. 11 ohms

Explanation
Find RT of parallel resistors: RT = 8x8/8+8 = 64/16 = 4
New R2 is RT of parallel resistors. Now use RT = R1 (7) + R2 (4) = 11 ohms

Rate this question:
9.

In a series-parallel circuit, the series current at I1 = 9 amps; in the two parallel branches, I2 = 5 amps; and the value of I3 is not listed. Use Ohms's law to find the value of I3 and IT.
- A.
  
  I3 = 5 amps and IT = 14 amps
- B.
  
  I3 = 4 amps and IT = 9 amps
- C.
  
  I3 = 4 amps and IT =18 amps
- D.
  
  Not enough information to solve
Correct Answer
B. I3 = 4 amps and IT = 9 amps

Explanation
Total current is equal throughout series part of circuit. So since I1 (in series part) = 9 amps, IT = 9 amps. Parallel branches always add up to equal current flow in series part. So, I2 (5 amps) + I3 (?) = 9 amps. I3 has to equal 4 amps.

Rate this question:
10.

What is the difference between and open and a short?
- A.
  
  An open causes resistance to decrease; a short causes resistance to increase
- B.
  
  Excessive current flow in an open circuit; no current flow in a shorted component
- C.
  
  No current flow in an open circuit; excessive current flow in a shorted component
- D.
  
  Minimum voltage development across the open component; maximum voltage development across the shorted component
Correct Answer
C. No current flow in an open circuit; excessive current flow in a shorted component

Explanation
An open circuit refers to a break or discontinuity in the circuit, which prevents the flow of current. In this case, there is no current flow. On the other hand, a short circuit occurs when there is an unintended connection between two points in the circuit, resulting in excessive current flow. Therefore, the correct answer states that there is no current flow in an open circuit, while there is excessive current flow in a shorted component.

Rate this question:
11.

Voltage induced into a conductor by the expanding and collapsing of a magnetic field is
- A.
  
  Magnetism
- B.
  
  Reluctance
- C.
  
  Direct current
- D.
  
  Electromagnetic induction
Correct Answer
D. Electromagnetic induction

Explanation
Electromagnetic induction is the correct answer because it refers to the process by which a voltage is induced in a conductor when it is exposed to a changing magnetic field. When the magnetic field expands or collapses, it creates a flux linkage with the conductor, resulting in the generation of an electromotive force (voltage) according to Faraday's law of electromagnetic induction. This phenomenon is the basis for the functioning of devices such as generators and transformers.

Rate this question:
12.

In an inductor, what happens to the magnetic lines of force if the diameter of the core is increased in size?
- A.
  
  Permeability increases
- B.
  
  Magnetic field decreases
- C.
  
  Induction of the coil increases
- D.
  
  Induction of the coil decreases
Correct Answer
C. Induction of the coil increases

Explanation
When the diameter of the core in an inductor is increased, the magnetic lines of force passing through the coil also increase. This is because a larger core allows for more magnetic flux to flow through it, resulting in a stronger magnetic field. As a result, the induction of the coil increases, meaning that the coil will generate a larger electromotive force (EMF) or voltage.

Rate this question:
13.

What is the basic principle of operation for transformers?
- A.
  
  Mutual induction
- B.
  
  Magnetic induction
- C.
  
  Counterelectromotive force
- D.
  
  Primary and secondary induction
Correct Answer
A. Mutual induction

Explanation
The basic principle of operation for transformers is mutual induction. Mutual induction refers to the phenomenon where a changing current in one coil induces a voltage in a nearby coil. In the case of transformers, the primary coil is connected to an alternating current source, which creates a changing magnetic field. This changing magnetic field induces a voltage in the secondary coil, allowing for the transfer of electrical energy from one circuit to another. Mutual induction is essential for the functioning of transformers and is the basis for their ability to step up or step down voltage levels.

Rate this question:
14.

What type of transformer contains more turns in the primary winding than in the secondary winding?
- A.
  
  Current
- B.
  
  Step up
- C.
  
  Rectifier
- D.
  
  Step down
Correct Answer
D. Step down

Explanation
A step-down transformer contains more turns in the primary winding than in the secondary winding. This type of transformer is used to decrease the voltage level from the primary side to the secondary side. By having more turns in the primary winding, the transformer can step down the voltage and increase the current in the secondary winding. This is commonly used in power distribution systems to deliver lower voltage levels to households and businesses.

Rate this question:
15.

If the size of the plates of a capacitor is increased, how is capacitance affected?
- A.
  
  Capacitance increases
- B.
  
  Capacitance decreases
- C.
  
  Electrons are distorted and scattered
- D.
  
  Electrostatic force between the plates decreases
Correct Answer
A. Capacitance increases

Explanation
When the size of the plates of a capacitor is increased, the distance between the plates decreases. This leads to an increase in the electric field between the plates, resulting in an increase in the capacitance. The capacitance of a capacitor is directly proportional to the size of the plates, so when the size is increased, the capacitance also increases.

Rate this question:
16.

What statement best describes a capacitive circuit?
- A.
  
  Current leads applied voltage by 90 degrees
- B.
  
  Applied voltage leads current by 90 degrees
- C.
  
  Has the ability to conduct in one direction and not in the other
- D.
  
  Has the ability to conduct in all directions when gated or discharged
Correct Answer
A. Current leads applied voltage by 90 degrees

Explanation
A capacitive circuit is one in which the current leads the applied voltage by 90 degrees. This means that the current reaches its peak value before the voltage does. Capacitors store and release electrical energy, and in a capacitive circuit, the flow of current is determined by the rate at which the voltage changes. As the voltage increases, the capacitor charges and allows current to flow, causing the current to lead the voltage. Therefore, the statement "current leads applied voltage by 90 degrees" best describes a capacitive circuit.

Rate this question:
17.

How many electrons does the valance band of an intrinsic semiconductor have?
- A.
  
  3
- B.
  
  4
- C.
  
  5
- D.
  
  6
Correct Answer
B. 4

Explanation
The valence band of an intrinsic semiconductor is the highest energy band that is fully occupied by electrons at absolute zero temperature. In an intrinsic semiconductor, each atom contributes one valence electron, which is shared with neighboring atoms to form covalent bonds. Since each atom has four valence electrons, the valence band of an intrinsic semiconductor has four electrons.

Rate this question:
18.

What are the minority carriers in P-type material?
- A.
  
  Holes
- B.
  
  Protons
- C.
  
  Neutrons
- D.
  
  Electrons
Correct Answer
D. Electrons

Explanation
In P-type material, the majority carriers are holes, which are positively charged. Minority carriers, on the other hand, are the minority of charge carriers present in the material. In P-type material, the minority carriers are electrons, which are negatively charged. These electrons are introduced into the material through the process of doping, where impurities are added to the material to create an excess of electrons.

Rate this question:
19.

The area of a semiconductor where P-type material is joined to N-type material is known as
- A.
  
  Dielectric region
- B.
  
  Depletion region
- C.
  
  Depletion field
- D.
  
  PN region
Correct Answer
B. Depletion region

Explanation
The area where P-type material is joined to N-type material in a semiconductor is known as the depletion region. This region is formed due to the diffusion of charge carriers from one region to another, resulting in the formation of a region depleted of majority charge carriers. The depletion region acts as a barrier to the flow of current until a sufficient voltage is applied to overcome this barrier.

Rate this question:
20.

A junction diode has how many PN junction(s)?
- A.
  
  1
- B.
  
  2
- C.
  
  3
- D.
  
  4
Correct Answer
A. 1

Explanation
A junction diode has only one PN junction. This junction is formed by the combination of a P-type semiconductor and an N-type semiconductor. The PN junction is responsible for the diode's unique electrical properties, such as allowing current to flow in only one direction and exhibiting forward and reverse bias characteristics.

Rate this question:
21.

In a circuit using a bridge rectifier, how many diodes are forward biased during the first cycle of alternating current (AC)?
- A.
  
  4
- B.
  
  3
- C.
  
  2
- D.
  
  1
Correct Answer
C. 2

Explanation
During the first cycle of alternating current (AC) in a circuit using a bridge rectifier, two diodes are forward biased. The bridge rectifier consists of four diodes arranged in a bridge configuration. During the positive half cycle of AC, two diodes (D1 and D3) are forward biased and conduct current, while the other two diodes (D2 and D4) are reverse biased and do not conduct. This allows the current to flow in one direction, converting AC to pulsating DC. Therefore, the correct answer is 2.

Rate this question:
22.

If a zener diode is installed in the forward bias mode in a circuit, it acts as a
- A.
  
  Regular diode
- B.
  
  Spike protector
- C.
  
  Voltage reference
- D.
  
  Voltage regulator
Correct Answer
A. Regular diode

Explanation
When a zener diode is installed in the forward bias mode, it behaves like a regular diode. In this mode, the diode allows current to flow in the forward direction, just like a normal diode. The zener diode will not exhibit its characteristic voltage regulation or voltage reference behavior in this configuration. Therefore, it acts as a regular diode in the forward bias mode.

Rate this question:
23.

How is a zener diode connected in a circuit to regulate voltage?
- A.
  
  In parallel to the load
- B.
  
  In series with the load
- C.
  
  In parallel to the resistor
- D.
  
  In series with the resistor
Correct Answer
A. In parallel to the load

Explanation
A zener diode is connected in parallel to the load in order to regulate voltage. By connecting it in parallel, the zener diode acts as a voltage regulator by maintaining a constant voltage across the load. When the voltage exceeds the zener voltage, the diode starts conducting and effectively regulates the voltage by diverting excess current. This ensures that the voltage across the load remains constant, even if the input voltage fluctuates.

Rate this question:
24.

If a schematic diagram doesn't list a reference for the zener diode, the diode is probably being used as a
- A.
  
  Reference
- B.
  
  Normal diode
- C.
  
  Spike protector
- D.
  
  Voltage regulator
Correct Answer
C. Spike protector

Explanation
If a schematic diagram doesn't list a reference for the zener diode, it is likely being used as a spike protector. A zener diode is a type of diode that is designed to operate in the reverse breakdown region, allowing it to regulate voltage and protect against voltage spikes. In this case, since there is no reference given for the zener diode, it is most likely being used to protect against voltage spikes rather than as a voltage regulator or a normal diode.

Rate this question:
25.

How is the zener diode connected in a circuit to protect the load?
- A.
  
  In parallel to the resistor
- B.
  
  In series with the load
- C.
  
  In parallel to the load
- D.
  
  Forward biased
Correct Answer
C. In parallel to the load

Explanation
The zener diode is connected in parallel to the load in order to protect it. When the voltage across the load exceeds the zener diode's breakdown voltage, the diode starts conducting and limits the voltage to its breakdown voltage. This prevents any excessive voltage from reaching the load and protects it from damage. Connecting the zener diode in parallel to the load ensures that it only conducts when necessary, providing effective protection.

Rate this question:
26.

What is the primary use of a silicon-controlled rectifier (SCR)?
- A.
  
  Electronic switch
- B.
  
  Voltage regulator
- C.
  
  Circuit amplifier
- D.
  
  Spike protector
Correct Answer
A. Electronic switch

Explanation
A silicon-controlled rectifier (SCR) is primarily used as an electronic switch. It is a semiconductor device that can control the flow of electric current. By applying a small voltage to the gate terminal, the SCR can be turned on and allow current to flow through it. Once triggered, it remains conducting even if the gate voltage is removed. This characteristic makes it suitable for applications where a high voltage or high current needs to be controlled, such as in power control circuits, motor control, and lighting dimmers.

Rate this question:
27.

The silicon-controlled rectifier (SCR) has how many layers?
- A.
  
  1
- B.
  
  2
- C.
  
  3
- D.
  
  4
Correct Answer
D. 4

Explanation
The silicon-controlled rectifier (SCR) has four layers. The SCR is a four-layer semiconductor device that acts as a switch, allowing current to flow in one direction. It consists of three P-N junctions and four layers of alternating P-type and N-type materials. The four layers are the anode layer, the cathode layer, and two layers known as the P1 and N1 layers. The four-layer structure of the SCR allows it to control high power levels and handle large currents.

Rate this question:
28.

If a small potential is applied to the gate of a silicon-controlled rectifier (SCR), the
- A.
  
  Middle junction of the SCR is reversed biased and the SCR turns off
- B.
  
  Middle junction of the SCR is forward biased and the SCR turns on
- C.
  
  Depletion region increases in size and blocks current flow
- D.
  
  Depletion region decreases in size and stops current flow
Correct Answer
B. Middle junction of the SCR is forward biased and the SCR turns on

Explanation
When a small potential is applied to the gate of a silicon-controlled rectifier (SCR), the middle junction of the SCR becomes forward biased. This means that the P-type material in the middle junction becomes more positive with respect to the N-type material. This forward biasing allows current to flow through the SCR and turns it on. As a result, the SCR conducts current from anode to cathode.

Rate this question:
29.

What is the major difference between an NPN transistor and a PNP transistor?
- A.
  
  A PNP transistor can only be used as a regulator
- B.
  
  An NPN transistor can only be used as a switch
- C.
  
  Direction of current flow
- D.
  
  Number of junctions
Correct Answer
C. Direction of current flow

Explanation
The major difference between an NPN transistor and a PNP transistor is the direction of current flow. In an NPN transistor, the current flows from the collector to the emitter, while in a PNP transistor, the current flows from the emitter to the collector. This difference in current flow direction is due to the arrangement of the layers of the transistor and the type of doping used.

Rate this question:
30.

If the arrow in a bipolar transistor is pointing away from the base, what type of transister is it?
- A.
  
  N-type
- B.
  
  P-type
- C.
  
  NPN
- D.
  
  PNP
Correct Answer
C. NPN

Explanation
If the arrow in a bipolar transistor is pointing away from the base, it indicates that the transistor is an NPN type. In an NPN transistor, the majority charge carriers are negative electrons, and the arrow points in the direction of the conventional current flow.

Rate this question:
31.

The circuit in the bipolar transistor that carries 5 percent of the current flow is the
- A.
  
  Basecircuit circuit
- B.
  
  Load circuit
- C.
  
  Control circuit
- D.
  
  Emmiter-collector
Correct Answer
C. Control circuit

Explanation
The control circuit in a bipolar transistor is responsible for regulating the flow of current through the transistor. It determines the amount of current that flows from the base to the emitter and controls the amplification of the signal. In this case, the control circuit carries 5 percent of the total current flow, indicating that it plays a significant role in controlling the transistor's operation.

Rate this question:
32.

What happens if the emitter-base (E-B) current is increased in a transistor amplifier?
- A.
  
  Resitance decreases and current through the load circuit decreases
- B.
  
  Current decreases through the emitter-collector (E-C) circuit
- C.
  
  Resistance increases and current flow decreases
- D.
  
  Current increases through the E-C circuit
Correct Answer
D. Current increases through the E-C circuit

Explanation
When the emitter-base (E-B) current is increased in a transistor amplifier, it causes an increase in the current through the emitter-collector (E-C) circuit. This is because the E-B current controls the amplification of the transistor, and increasing it allows more current to flow through the E-C circuit. Therefore, the correct answer is that the current increases through the E-C circuit.

Rate this question:
33.

How many junctions are in a unijunction transister (UJT)?
- A.
  
  1
- B.
  
  2
- C.
  
  3
- D.
  
  4
Correct Answer
A. 1

Explanation
A unijunction transistor (UJT) typically has one junction. This junction is formed between the emitter and the base regions of the transistor. The UJT operates by controlling the current flow between the emitter and the base, making it a useful device for applications such as oscillators and timing circuits.

Rate this question:
34.

What are the three leads in a unijunction transistor (UJT) called?
- A.
  
  Anode, cathose, and gate
- B.
  
  Emitter, base 1, and base 2
- C.
  
  Emitter, collector, and base
- D.
  
  Common emitter, common collector, and common base
Correct Answer
B. Emitter, base 1, and base 2

Explanation
The three leads in a unijunction transistor (UJT) are called emitter, base 1, and base 2.

Rate this question:
35.

The emitter in a unijunction transister always points toward the
- A.
  
  Base 1 lead
- B.
  
  Collector
- C.
  
  Emitter
- D.
  
  Gate
Correct Answer
A. Base 1 lead

Explanation
The emitter in a unijunction transistor always points toward the base 1 lead. This is because the base 1 lead is the primary terminal that controls the operation of the transistor. The emitter is responsible for emitting the majority charge carriers (electrons or holes) into the base region, and it needs to be oriented towards the base 1 lead for proper functioning. The collector is the terminal that collects the charge carriers, and the gate is not relevant to a unijunction transistor.

Rate this question:
36.

The amount of voltage it takes for a unijunction transistor (UJT) to fire is determined by the position
- A.
  
  The emitter is placed on the N-type material
- B.
  
  The emitter is placed on the P-type material
- C.
  
  Of B1 and B2 on the P-type material
- D.
  
  Of the UJT in the circuit
Correct Answer
A. The emitter is placed on the N-type material

Explanation
The correct answer is the emitter is placed on the N-type material. In a unijunction transistor (UJT), the voltage required for it to fire is determined by the position of the emitter on the N-type material. The emitter is responsible for controlling the conductivity of the UJT. Placing the emitter on the N-type material allows for better control of the firing voltage.

Rate this question:
37.

What controls the firing time of the unijunction transistor (UJT)?
- A.
  
  Intrinsic standoff ratio
- B.
  
  Resistance in the circuit
- C.
  
  Capacitance in the circuit
- D.
  
  Resistance and capacitance in the circuit
Correct Answer
D. Resistance and capacitance in the circuit

Explanation
The firing time of the unijunction transistor (UJT) is controlled by the resistance and capacitance in the circuit. The resistance determines the charging and discharging time of the capacitor, while the capacitance determines the rate at which the capacitor charges and discharges. By adjusting the values of resistance and capacitance, the firing time of the UJT can be controlled.

Rate this question:
38.

In what position must the line drop switch be placed when adjustments are made to a voltage regulator?
- A.
  
  ON
- B.
  
  OFF
- C.
  
  Adjust
- D.
  
  Regulator
Correct Answer
A. ON

Explanation
The line drop switch must be placed in the "ON" position when adjustments are made to a voltage regulator. This is because the switch is responsible for controlling the flow of electricity in the circuit. By turning it on, the circuit is closed and allows the regulated voltage to be adjusted and controlled.

Rate this question:
39.

What component of the voltage regulator compensates for losses in the power cable by sensing changes in current flow?
- A.
  
  Load rheostat
- B.
  
  No load rheostat
- C.
  
  Line drop switch
- D.
  
  Voltage adjustment rheostat
Correct Answer
A. Load rheostat

Explanation
The load rheostat is the component of the voltage regulator that compensates for losses in the power cable by sensing changes in current flow. It adjusts the resistance in the circuit to regulate the voltage and ensure that the desired voltage is maintained, compensating for any losses in the power cable.

Rate this question:
40.

The portion of the voltage regulator that supplies exciter field voltage is transformer
- A.
  
  (T1) and rectifier (B3)
- B.
  
  (T3) and rectifier (B2)
- C.
  
  (T2) and rectifier (B1)
- D.
  
  (T1) and rectifier (CR26)
Correct Answer
D. (T1) and rectifier (CR26)

Explanation
The correct answer is (T1) and rectifier (CR26). The voltage regulator supplies exciter field voltage through a transformer (T1) and a rectifier (CR26). The transformer steps up or steps down the voltage to the required level, while the rectifier converts the AC voltage into DC voltage. Together, they provide the exciter field voltage necessary for the voltage regulator to regulate the output voltage of the generator. The other options mentioned (T2, B1, T3, B2, B3) are not involved in supplying the exciter field voltage.

Rate this question:
41.

Refer to foldout 1. After performing an ops check of the -86 generator set, you proceed to shut the unit down. After the generator stops, you notice the engine on light continues to glow. What is the probable cause of this trouble?
- A.
  
  S46 open
- B.
  
  S48 open
- C.
  
  S46 closed
- D.
  
  S48 closed
Correct Answer
D. S48 closed

Explanation
The probable cause of the engine on light continuing to glow after shutting down the generator is that S48 is closed.

Rate this question:
42.

Refer to foldout 1. During operation of the -86D, you get no response when you place S13 in the GENERATE position. A check of voltage at J8, terminal N, shows 12 volts direct current (VDC). What is the probable cause of this trouble?
- A.
  
  M4 is open
- B.
  
  S53 is open
- C.
  
  K23 is open
- D.
  
  K16 is open
Correct Answer
B. S53 is open

Explanation
The probable cause of the trouble is that S53 is open. This can be inferred from the given information that there is no response when S13 is placed in the GENERATE position, and a check of voltage at J8, terminal N, shows 12 volts DC. Since S53 is open, it means that there is a break in the circuit and the current cannot flow through it, resulting in no response during operation.

Rate this question:
43.

Refer to foldout 1. You are operating -86D at governed speed, but voltage doesn't build up. What is the probable cause of this trouble?
- A.
  
  S1 is in the automatic position
- B.
  
  R61 is turned fully clockwise
- C.
  
  K16 contacts are closing
- D.
  
  K23 contacts are open
Correct Answer
D. K23 contacts are open

Explanation
The probable cause of the trouble is that the K23 contacts are open. This means that there is no electrical connection being made, which is preventing the voltage from building up.

Rate this question:
44.

Refer to foldout 1. During an ops check of the -86D, the shutdown solenoid energizes immediately after the engine run indicator illluminates. What is a probable cause of this trouble?
- A.
  
  S48 open
- B.
  
  S46 open
- C.
  
  S49 shorted
- D.
  
  S22 stuck open
Correct Answer
C. S49 shorted

Explanation
The probable cause of the shutdown solenoid energizing immediately after the engine run indicator illuminates is that S49 is shorted.

Rate this question:
45.

Refer to foldout 1. During operation of the -86D, the low coolant light (DS50) illuminates, but the unit does not shut down. What is a probable cause of this trouble?
- A.
  
  A2
- B.
  
  DS50
- C.
  
  S55 is closed
- D.
  
  S48 is closed
Correct Answer
A. A2

Explanation
The probable cause of the low coolant light (DS50) illuminating but the unit not shutting down is that S55 is closed.

Rate this question:
46.

Refer to foldout 1. Which statement best reflects what happens if S46 shorts during operation of a -86D generator?
- A.
  
  12 VDC would be present at terminal A of S55
- B.
  
  There would be no change to unit operation
- C.
  
  M5 would go into an overspeed condition
- D.
  
  S55 would ause L6 to de-energize
Correct Answer
A. 12 VDC would be present at terminal A of S55

Explanation
If S46 shorts during operation of a -86D generator, 12 VDC would be present at terminal A of S55.

Rate this question:
47.

What component controls the strength of the -86D exciter field L2?
- A.
  
  Excitation relay K16
- B.
  
  Time delay relay K14
- C.
  
  Voltage regulator VR1
- D.
  
  Automatic manual switch S1
Correct Answer
C. Voltage regulator VR1

Explanation
The voltage regulator VR1 controls the strength of the -86D exciter field L2. This means that VR1 determines the amount of voltage supplied to the exciter field, which in turn affects the strength of the field. By adjusting the voltage, the voltage regulator can control the strength of the exciter field, allowing for precise control over the generator's output.

Rate this question:
48.

Refer to foldout 1. Where is the best point to check voltage to the -86D exciter field?
- A.
  
  J8, terminal D-F
- B.
  
  J8, terminal V-X
- C.
  
  VR1. terminal C-R
- D.
  
  Automatic-manual switch S1
Correct Answer
A. J8, terminal D-F

Explanation
The best point to check voltage to the -86D exciter field is at J8, terminal D-F.

Rate this question:
49.

A -86D is operating and the alternating current (AC) voltmeter is reading 200 volts alternating current (VAC) on all three phases. What do you do?
- A.
  
  Adjust VR1
- B.
  
  Adjust R61
- C.
  
  Adjust VR1 or R61
- D.
  
  Switch S15 to the L-N position
Correct Answer
D. Switch S15 to the L-N position

Explanation
Switch S15 to the L-N position. This action will change the voltmeter measurement from 200 volts AC to line-to-neutral voltage, which is the correct measurement for a three-phase system. Adjusting VR1 or R61 would not address the issue of incorrect voltage measurement.

Rate this question:
50.

Refer to foldout 1. A -86D is sent to the the shop on a Red X for "will not apply power to the aircraft." During the ops check, you place S5 in the closed position and the contactor light illuminates. When you release the switch, the contactor opens. What is the probable cause of this trouble?
- A.
  
  S2 is open
- B.
  
  R46 is open
- C.
  
  K2 is closed
- D.
  
  K17 is closed
Correct Answer
B. R46 is open

Explanation
The probable cause of this trouble is that R46 is open. This can be inferred from the given information that when S5 is placed in the closed position, the contactor light illuminates, indicating that the circuit is closed. However, when the switch is released, the contactor opens, suggesting that there is an issue with the circuit. Since R46 is the only component mentioned in the options that could cause this problem, it is the most likely cause.

Rate this question:

Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

Current Version
Mar 20, 2023

Quiz Edited by
ProProfs Editorial Team
Feb 10, 2010

Quiz Created by
Cocoanut

2A672 Volume 1 Ure Questions

What is the simplest form of matter?

In an atom, what electrons contain the most energy?

Atoms having more than four electrons, but less than eight are known as

The electrostatic fields around a positive ion move

What are factors that affect the resistance of a material?

What is the resistance in a circuit if the power rating is 40 watts and total current is 2 amps?

Convert 500 milliamps to standard amperage.

In a series-parallel circuit, find RT if series resistor R1 = 7 ohms, and parallel resistors R2 and R3 = 8 ohms.

In a series-parallel circuit, the series current at I1 = 9 amps; in the two parallel branches, I2 = 5 amps; and the value of I3 is not listed. Use Ohms's law to find the value of I3 and IT.

What is the difference between and open and a short?

Voltage induced into a conductor by the expanding and collapsing of a magnetic field is

In an inductor, what happens to the magnetic lines of force if the diameter of the core is increased in size?

What is the basic principle of operation for transformers?

What type of transformer contains more turns in the primary winding than in the secondary winding?

If the size of the plates of a capacitor is increased, how is capacitance affected?

What statement best describes a capacitive circuit?

How many electrons does the valance band of an intrinsic semiconductor have?

What are the minority carriers in P-type material?

The area of a semiconductor where P-type material is joined to N-type material is known as

A junction diode has how many PN junction(s)?

In a circuit using a bridge rectifier, how many diodes are forward biased during the first cycle of alternating current (AC)?

If a zener diode is installed in the forward bias mode in a circuit, it acts as a

How is a zener diode connected in a circuit to regulate voltage?

If a schematic diagram doesn't list a reference for the zener diode, the diode is probably being used as a

How is the zener diode connected in a circuit to protect the load?

What is the primary use of a silicon-controlled rectifier (SCR)?

The silicon-controlled rectifier (SCR) has how many layers?

If a small potential is applied to the gate of a silicon-controlled rectifier (SCR), the

What is the major difference between an NPN transistor and a PNP transistor?

If the arrow in a bipolar transistor is pointing away from the base, what type of transister is it?

The circuit in the bipolar transistor that carries 5 percent of the current flow is the

What happens if the emitter-base (E-B) current is increased in a transistor amplifier?

How many junctions are in a unijunction transister (UJT)?

What are the three leads in a unijunction transistor (UJT) called?

The emitter in a unijunction transister always points toward the

The amount of voltage it takes for a unijunction transistor (UJT) to fire is determined by the position

What controls the firing time of the unijunction transistor (UJT)?

In what position must the line drop switch be placed when adjustments are made to a voltage regulator?

What component of the voltage regulator compensates for losses in the power cable by sensing changes in current flow?

The portion of the voltage regulator that supplies exciter field voltage is transformer

Refer to foldout 1. After performing an ops check of the -86 generator set, you proceed to shut the unit down. After the generator stops, you notice the engine on light continues to glow. What is the probable cause of this trouble?

Refer to foldout 1. During operation of the -86D, you get no response when you place S13 in the GENERATE position. A check of voltage at J8, terminal N, shows 12 volts direct current (VDC). What is the probable cause of this trouble?

Refer to foldout 1. You are operating -86D at governed speed, but voltage doesn't build up. What is the probable cause of this trouble?

Refer to foldout 1. During an ops check of the -86D, the shutdown solenoid energizes immediately after the engine run indicator illluminates. What is a probable cause of this trouble?

Refer to foldout 1. During operation of the -86D, the low coolant light (DS50) illuminates, but the unit does not shut down. What is a probable cause of this trouble?

Refer to foldout 1. Which statement best reflects what happens if S46 shorts during operation of a -86D generator?

What component controls the strength of the -86D exciter field L2?

Refer to foldout 1. Where is the best point to check voltage to the -86D exciter field?

A -86D is operating and the alternating current (AC) voltmeter is reading 200 volts alternating current (VAC) on all three phases. What do you do?

Refer to foldout 1. A -86D is sent to the the shop on a Red X for "will not apply power to the aircraft." During the ops check, you place S5 in the closed position and the contactor light illuminates. When you release the switch, the contactor opens. What is the probable cause of this trouble?