1.
What is the simplest form of matter?
Correct Answer
A. Element
Explanation
An element is the simplest form of matter because it consists of only one type of atom. It cannot be broken down into simpler substances by chemical means. In contrast, a compound is made up of two or more different elements chemically combined, while a mixture is a combination of different substances that are not chemically bonded. Electrons are subatomic particles and not a form of matter on their own. Therefore, the correct answer is element.
2.
In an atom, what electrons contain the most energy?
Correct Answer
C. Valence electrons
Explanation
Valence electrons contain the most energy in an atom. Valence electrons are the outermost electrons in an atom's electron cloud and are involved in chemical reactions. These electrons are farther from the nucleus and experience less attraction, resulting in higher energy levels. The other options, such as orbiting electrons and K shell electrons, are not necessarily incorrect, but they do not specifically refer to the electrons with the most energy.
3.
If there are eight electrons in the outer most sheel of an atom, then its considered
Correct Answer
D. Stable
Explanation
If there are eight electrons in the outermost shell of an atom, it is considered stable. This is because the octet rule states that atoms tend to gain, lose, or share electrons in order to achieve a stable configuration with eight electrons in their outermost shell. Having a full outer shell of electrons makes the atom less likely to react with other atoms and more stable overall.
4.
Atoms having more then four electrons, but less than eight atoms are known as
Correct Answer
A. Insulators
Explanation
Atoms having more than four electrons but less than eight electrons in their outermost energy level are known as insulators. Insulators are materials that do not conduct electricity easily because their outermost energy level is almost full, making it difficult for electrons to move freely. This lack of mobility of electrons prevents the flow of electric current through the material, thereby making it a poor conductor of electricity.
5.
The electrostatic field around a positive ion move
Correct Answer
B. Outward
Explanation
The electrostatic field around a positive ion moves outward. This is because positive ions have a deficiency of electrons, resulting in a net positive charge. The positive charge attracts negatively charged particles, causing the electrostatic field to extend outward from the ion.
6.
The force required to move free electrons through a conductor is known as
Correct Answer
B. Voltage
Explanation
Voltage is the correct answer because it represents the force or electric potential difference that drives the movement of free electrons through a conductor. It is the measure of the energy per unit charge required to move the electrons, and it determines the rate of flow of electric current. The greater the voltage, the stronger the force pushing the electrons, and the higher the current.
7.
What are factors that affect the resistance of a material?
Correct Answer
B. Area, temperature, and type of material
Explanation
The factors that affect the resistance of a material are the area, temperature, and type of material. The area of the material affects the resistance because a larger area allows for more current to flow, resulting in lower resistance. The temperature of the material affects the resistance because as temperature increases, the resistance also increases. Lastly, the type of material affects the resistance because different materials have different resistivities, which determine their resistance.
8.
What is the resistance in a circuit if the power rating is 40 watts and total current is 2 amps?
Correct Answer
C. 10 ohms
Explanation
The power rating of a circuit is equal to the product of the current flowing through it and the resistance. In this question, the power rating is given as 40 watts and the total current is 2 amps. By rearranging the formula, we can calculate the resistance by dividing the power rating by the current. Therefore, the resistance in the circuit is 40 watts divided by 2 amps, which equals 20 ohms.
9.
In a series-parallel circuit, find RT (total resistance) if series resistor R1=7 ohms, and parallel resistor R2 and R3= 8 ohms.
Correct Answer
C. 11 ohms
Explanation
In a series-parallel circuit, the total resistance (RT) is calculated by adding the resistances in the series portion and the reciprocal of the sum of the reciprocals of the resistances in the parallel portion. In this case, the series resistor R1 is 7 ohms, and the parallel resistors R2 and R3 are 8 ohms each. The sum of the series resistors is 7 ohms. The reciprocal of the sum of the reciprocals of the parallel resistors is 1/((1/8)+(1/8)) = 4 ohms. Adding the series and parallel portions, we get 7 ohms + 4 ohms = 11 ohms, which is the total resistance (RT) in the circuit.
10.
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 Ohm's law to find the value of I3 and IT.
Correct Answer
B. I3 = 4 AMPS AND IT = 9 AMPS
Explanation
In a series-parallel circuit, the total current (IT) is equal to the sum of the currents in the series and parallel branches. In this case, the series current (I1) is given as 9 amps and the parallel current (I2) is given as 5 amps. To find the total current, we add these two currents together: IT = I1 + I2 = 9 + 5 = 14 amps. Since the value of I3 is not listed, we cannot determine its value. Therefore, the correct answer is I3 = 4 amps and IT = 9 amps.
11.
In a series-parallel circuit, total voltage is 2 volts, the value of E1 in the series portion of the circuit is unknown. There are two parallel branches (E2 = 3 volts) and the valueof E3 in the second parallel branch is unknown. Using Ohms law, find the value of E1 and E3.
Correct Answer
D. E3 = 3 VOLTS AND E1 = 9 VOLTS
12.
What is the differnece between and open and a short?
Correct Answer
C. No current flow in an open circuit; excessive current flow in a shorted component.
Explanation
The correct answer explains that in an open circuit, there is no current flow, while in a shorted component, there is excessive current flow. This means that an open circuit acts as a break in the circuit, preventing the flow of current, while a shorted component creates a direct path for current to flow, resulting in an excessive amount of current.
13.
When voltage is induced into a conductor by a relative motion between the conductor and a magnetic field this principle is known as
Correct Answer
D. Electromagnetic induction
Explanation
Electromagnetic induction is the principle that explains the generation of voltage in a conductor when there is a relative motion between the conductor and a magnetic field. This phenomenon was discovered by Michael Faraday in the 19th century and is the basis for the functioning of generators and transformers. It is a fundamental principle in electromagnetism and plays a crucial role in various electrical and electronic devices.
14.
In an inductive circuit, what is meant by current lags volatge by 90 degrees?
Correct Answer
B. Current is maximum when voltage is zero; voltage is maximum when current is zero.
Explanation
In an inductive circuit, current lags voltage by 90 degrees means that the current reaches its maximum value when the voltage is at its minimum value, and vice versa. This is because in an inductive circuit, the current takes time to build up due to the presence of inductance, causing it to lag behind the voltage. When the voltage is at its maximum value, the current has not yet reached its maximum and is still increasing. Similarly, when the current is at its maximum value, the voltage has already started to decrease.
15.
What is the basic principle of operation for transformers?
Correct Answer
A. Mutual induction
Explanation
The basic principle of operation for transformers is mutual induction. Mutual induction refers to the process where a changing current in the primary coil of a transformer induces a voltage in the secondary coil. This is achieved through the magnetic field generated by the primary coil, which then links and induces a voltage in the secondary coil. Mutual induction allows for the transfer of electrical energy from one coil to another without direct electrical connection, making transformers an essential component in electrical power distribution systems.
16.
What transformer winding acts as a conductor and provides the path into which the voltage is induced?
Correct Answer
C. Secondary
Explanation
The secondary winding of a transformer acts as a conductor and provides the path into which the voltage is induced. When an alternating current is applied to the primary winding, it creates a changing magnetic field which induces a voltage in the secondary winding. This voltage can then be used to power electrical devices or be further transformed to different voltage levels. The secondary winding is typically connected to the load and is responsible for delivering the desired output voltage.
17.
If the size of the plates or a capacitor is increased, how is capacitance affected?
Correct Answer
A. Capacitance increases
Explanation
When the size of the plates or a capacitor is increased, the distance between the plates also increases. This results in an increase in the capacitance. Capacitance is directly proportional to the surface area of the plates and inversely proportional to the distance between them. Therefore, when the size of the plates or the capacitor is increased, the capacitance increases.
18.
What statement best describes a capacitive circuit?
Correct Answer
A. Current leads applied voltage by 90 degrees.
Explanation
A capacitive circuit is characterized by the fact that the current flowing through it leads the applied voltage by 90 degrees. This means that the current reaches its maximum value before the voltage does. Capacitors store and release electrical energy, and this phase shift between current and voltage is a result of the way the capacitor charges and discharges.
19.
In what type of circut(s) does a capacitor oppose any change in voltage?
Correct Answer
D. AC
Explanation
A capacitor opposes any change in voltage in AC circuits because it can store and release electrical energy in response to alternating current. As the AC voltage changes direction, the capacitor charges and discharges, creating a phase shift between the voltage and current. This opposition to voltage change is due to the ability of the capacitor to store charge and resist sudden changes in voltage. In DC circuits, the capacitor charges to a steady voltage and does not oppose any change in voltage, making it ineffective in this case. Therefore, the correct answer is AC.
20.
What statement best discribes a diode?
Correct Answer
C. Has the ability to conduct in one direction and not the other
Explanation
A diode is a semiconductor device that allows current to flow in one direction but blocks it in the opposite direction. This property is known as rectification and is the fundamental characteristic of a diode. It is commonly used in electronic circuits to control the flow of current and to convert AC to DC.
21.
What are the minority carriers in a P-type material?
Correct Answer
D. Electrons
Explanation
In a P-type material, majority carriers are holes, which are created due to the presence of acceptor impurities. Minority carriers, on the other hand, are the carriers that are present in lower concentrations compared to the majority carriers. In a P-type material, the minority carriers are electrons. These electrons are thermally generated and are present in small numbers due to the low concentration of donor impurities in the material. Therefore, the correct answer is electrons.
22.
The area of a semiconductor where the P-type material is joined tp N-type materials is known as
Correct Answer
B. Depletion region
Explanation
The correct answer is depletion region. In a semiconductor, the depletion region refers to the area where the P-type material and N-type materials are joined. This region is created due to the diffusion of charge carriers and the formation of a depletion layer, which results in a lack of free charge carriers. The depletion region plays a crucial role in the operation of semiconductor devices such as diodes and transistors.
23.
A junction diode has how many PN junction(s)?
Correct Answer
A. 1
Explanation
A junction diode has only one PN junction. A PN junction is formed when a P-type semiconductor is joined with an N-type semiconductor. This junction creates a barrier that allows current to flow in one direction and blocks it in the opposite direction. This characteristic of the PN junction is what makes a diode useful in various electronic applications such as rectification and switching.
24.
If a negative potential is connected to cathode and a positive potential is connected to anode of a PN junction, the diode is
Correct Answer
B. Forward biased
Explanation
When a negative potential is connected to the cathode and a positive potential is connected to the anode of a PN junction, the diode is forward biased. In this configuration, the positive potential attracts the free electrons in the N-region towards the junction, while the negative potential attracts the holes in the P-region towards the junction. This creates a low resistance path for current to flow through the diode, allowing current to flow from the anode to the cathode. Therefore, the diode is forward biased in this scenario.
25.
In a circuit using a bridge rectifier, how many diodes are forward biased during the first cycle of alternating current (AC)
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 the AC, two diodes become forward biased and conduct, allowing the current to flow through them. The other two diodes become reverse biased and do not conduct. This arrangement ensures that the AC input is converted into a pulsating DC output.
26.
How is a zener diod connected in a circuit to regulate voltage?
Correct Answer
A. In paralle to the load
Explanation
A zener diode is connected in parallel to the load in a circuit to regulate voltage. When connected in this way, the zener diode acts as a voltage regulator by maintaining a constant voltage across the load. It does this by conducting current in the reverse direction once the voltage across it exceeds its breakdown voltage. This ensures that the voltage across the load remains constant, even if the input voltage fluctuates. Connecting the zener diode in parallel to the load allows it to shunt excess current and maintain a stable voltage output.
27.
How is the zener diode connected in a circuit to protect the load?
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 breakdown voltage of the zener diode, it starts conducting and regulates the voltage, preventing it from exceeding a certain limit. This ensures that the load receives a constant voltage and is protected from any voltage spikes or surges.
28.
What is the primary use of silicon-controlled rectifier (SCR)
Correct Answer
A. Electronic switch
Explanation
The primary use of a silicon-controlled rectifier (SCR) is as an electronic switch. An SCR is a semiconductor device that can control the flow of electric current. It can be turned on or off using a small control signal, allowing it to act as a switch in various electronic circuits. This makes it useful for applications such as power control, motor control, and lighting control, where precise switching of electrical currents is required.
29.
The silicon-controlled rectifier (SCR) has how many layers?
Correct Answer
D. 4
Explanation
The silicon-controlled rectifier (SCR) is a four-layer semiconductor device that acts as a switch. It consists of three P-N junctions and four layers of alternating P-type and N-type material. The four layers are arranged in a specific order - P-N-P-N - which allows the SCR to control the flow of current in a circuit.
30.
In order to turn off a silicon-controlled rectifier(SCR) the current must drop below the
Correct Answer
B. Holding current
Explanation
The correct answer is holding current. When a silicon-controlled rectifier (SCR) is turned on, it requires a certain amount of current, known as the holding current, to keep it conducting. If the current drops below this holding current, the SCR will turn off. The holding current is necessary to maintain the conduction state of the SCR and prevent it from turning off unintentionally.
31.
What is the major difference between an NPN transistor and a PNP transistor?
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 and polarity of the transistor's layers and junctions.
32.
If the arrow in a bipolar transistor is pointing away from the base, what type of transistor is it?
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 electrons, and the arrow represents the direction of the conventional current flow. The base region is P-type, while the emitter and collector regions are N-type. The arrow pointing away from the base signifies the flow of electrons from the emitter to the collector, which is characteristic of an NPN transistor.
33.
The most positive point in a PNP bipolar transistor is the
Correct Answer
C. Emitter
Explanation
The emitter is the most positive point in a PNP bipolar transistor because it is connected to the positive terminal of the power supply. This allows current to flow from the emitter to the base and collector, enabling the transistor to amplify signals and control the flow of current in the circuit. The emitter is responsible for emitting the majority charge carriers (electrons or holes) into the base region, which then controls the transistor's behavior.
34.
The current in a bipolar transistor that carries 5 percent of the current flow is the
Correct Answer
C. Control circuit
Explanation
The correct answer is the control circuit. In a bipolar transistor, the control circuit is responsible for regulating and controlling the flow of current. It determines the amount of current that flows through the transistor by varying the voltage at the base terminal. The control circuit plays a crucial role in amplifying and switching signals in electronic devices.
35.
What happens if the emitter-base (E-B) current is increased in a transistor amplifier?
Correct Answer
D. Current increases through the E_C circuit
Explanation
When the emitter-base (E-B) current is increased in a transistor amplifier, the current through the emitter-collector (E-C) circuit also increases. This is because the emitter-base junction acts as a forward-biased diode, allowing more current to flow from the emitter to the collector. As a result, the resistance in the E-C circuit decreases, allowing more current to flow through it. Therefore, the correct answer is that the current increases through the E-C circuit.
36.
What are the three leads in a unijunction transistor (UJT) called?
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.
37.
The emitter in a unijunction transistor (UJT) always points towards the
Correct Answer
A. Base 1 lead
Explanation
In a unijunction transistor (UJT), the emitter always points towards the base 1 lead. This is because the base 1 lead is connected to the emitter region of the UJT. The emitter is responsible for emitting the majority charge carriers (electrons or holes) into the base region, which then controls the conductivity of the UJT. By pointing the emitter towards the base 1 lead, the UJT is able to properly function and regulate its conductivity.
38.
What controls the firetime in a unijuction transistor(UJT)?
Correct Answer
D. Resistance and capacitance in the circut
Explanation
The firetime in a unijunction transistor (UJT) is controlled by the resistance and capacitance in the circuit. The resistance determines the charging rate of the capacitor, while the capacitance determines the time it takes for the capacitor to charge. Together, the resistance and capacitance determine the timing of the UJT's firing, making them crucial factors in controlling the firetime.
39.
A metal oxide varistor (MOV) is made up of how many semiconductors?
Correct Answer
A. 2
Explanation
A metal oxide varistor (MOV) is made up of two semiconductors. This is because a MOV is a type of voltage-dependent resistor that is commonly used to protect electrical devices from voltage surges or spikes. It consists of a ceramic material made up of zinc oxide grains, which act as the semiconductors. These grains are sandwiched between two metal plates, forming the structure of the MOV. When a voltage surge occurs, the semiconducting properties of the zinc oxide grains allow the MOV to conduct and absorb the excess energy, protecting the connected devices.
40.
What components of the voltage regulator compensates losses in the power cable by sensing change in current flow?
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 maintain a constant voltage output, compensating for any voltage drop caused by losses in the cable. This ensures that the desired voltage is delivered to the load, regardless of any variations in the current flow.
41.
The portion of the voltage regulator that supplies exciter field voltage is tranformer
Correct Answer
D. (T1) and rectifier (CR26)
Explanation
The correct answer is (T1) and rectifier (CR26). This is because the exciter field voltage is supplied by the transformer (T1) and rectifier (CR26) combination. The transformer steps up or steps down the input voltage to the desired level, and the rectifier converts the alternating current (AC) output of the transformer into direct current (DC) to supply the exciter field voltage.
42.
Refer to fold out 1. After performing an operational check of the A/M32A-86D generator set, you proceed to shut the unit down. After the generator stops, you notice the engine on light continues to glow. What is a probable cause of this trouble?
Correct Answer
D. S48 closed
Explanation
The probable cause of the engine on light continuing to glow after shutting down the A/M32A-86D generator set is that S48 is closed.
43.
Refer to fold out 1. During operation of the A/M32A-86D generator set, you get no response when you place S13 in the GENERATE position. A check of volateg at J8, terminal N, shows 12 volts direct current(VDC). What is a probable cause of this trouble?
Correct Answer
B. S53 is open
Explanation
The probable cause of the trouble is that S53 is open. This means that the switch S53, which is responsible for generating power in the generator set, is not functioning properly. As a result, there is no response when S13 is placed in the GENERATE position. The check of voltage at J8, terminal N, shows 12 volts direct current (VDC), indicating that power is not being generated.
44.
Refer to fold out 1. You are operating an A/M32A-86D generator set at governed speed, but voltage doesnt build up. what is the probable cause of this trouble?
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 a break in the circuit, preventing the voltage from building up.
45.
During operation of the AM32A-86D generator set, what position do you place control switch S13 in to move the fuel rack and increase the engine speed to 2000 revolutions per minute(RPM)?
Correct Answer
B. GENERATE
Explanation
During operation of the AM32A-86D generator set, the control switch S13 should be placed in the "GENERATE" position to move the fuel rack and increase the engine speed to 2000 RPM. This position allows the generator to produce the necessary power output for generating electricity.
46.
Refer to fold out 1. During operation check of the A/M32A-86D generator set, the shutdown solinoid energized immediatly after engine run indicator illuminated. What is the probable cause of this trouble?
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.
47.
Refer to foldout 1. During operation of the A/M32A-86D generator set, the low coolant light (DS50) illuminates, but the unit does not shut down. What is the probable cause of this touble?
Correct Answer
A. A2
Explanation
The probable cause of the low coolant light (DS50) illuminating but the unit not shutting down is that S55 and S48 are closed.
48.
What component controls the strenght of the A/M32A-86D generator exciter field L2?
Correct Answer
C. Voltage regulator VR1
Explanation
The voltage regulator VR1 controls the strength of the A/M32A-86D generator exciter field L2. This means that VR1 is responsible for regulating the voltage output of the generator, which in turn determines the strength of the exciter field. By adjusting the voltage, VR1 ensures that the exciter field is at the desired level, which is crucial for the proper functioning of the generator.
49.
What component of the A/M32A-86D generator set is used to manually increase output voltage?
Correct Answer
A. Voltage rheostat R61
Explanation
The voltage rheostat R61 is used to manually increase the output voltage of the A/M32A-86D generator set. A voltage rheostat is a variable resistor that can be adjusted to control the flow of current in a circuit, thereby changing the voltage. By adjusting the voltage rheostat R61, the user can manually increase the output voltage of the generator set to the desired level.
50.
Refer to foldout 1. Where is the best point to check voltage to the A/M32A-86D generator exciter field?
Correct Answer
A. J8, terminal D-F
Explanation
The best point to check voltage to the A/M32A-86D generator exciter field is at J8, terminal D-F.