1.
(201) Every atom must contain these types of particles.
Correct Answer
A. Electrons and protons.
Explanation
Atoms are composed of three main types of particles: electrons, protons, and neutrons. Electrons are negatively charged particles that orbit around the nucleus of an atom. Protons are positively charged particles found in the nucleus of an atom. Neutrons are neutral particles also found in the nucleus. Therefore, the correct answer is electrons and protons, as both are essential components of every atom.
2.
(201) Up to how many valence electrons are needed to make a good conductor?
Correct Answer
A. 3.
Explanation
Valence electrons are the outermost electrons in an atom's electron cloud, and they are responsible for the atom's ability to conduct electricity. Good conductors typically have a small number of valence electrons, as these electrons are more easily able to move between atoms and carry an electric current. Therefore, the fewer valence electrons an atom has, the better conductor it will be. Option 3, which states that up to 3 valence electrons are needed to make a good conductor, aligns with this explanation.
3.
(201) The term "dielectric" is used to describe
Correct Answer
B. Insulators.
Explanation
The term "dielectric" is used to describe insulators. Dielectrics are materials that do not conduct electricity easily and are often used to separate conductive materials in order to prevent the flow of electric current. They have high resistivity and can withstand high voltages without breaking down. Dielectrics are commonly used in capacitors and electrical insulation applications.
4.
(202) This defines the flow or drift of electrons through a conductor in the same direction at the same time.
Correct Answer
C. Current.
Explanation
This question is asking for the term that defines the flow or drift of electrons through a conductor in the same direction at the same time. The correct answer is "Current." Current refers to the flow of electric charge, typically carried by electrons, in a conductor. It is measured in units of amperes (A) and is defined as the rate of flow of charge per unit of time. Conductivity refers to the ability of a material to conduct electric current, voltage is the electrical potential difference between two points, and valence refers to the combining capacity of an atom.
5.
(202) This is used to control current flow in a circuit.
Correct Answer
C. Resistance.
Explanation
Resistance is the property of a material that opposes the flow of electric current. It is used to control the current flow in a circuit by limiting the amount of current that can pass through. Voltage, on the other hand, is the potential difference between two points in a circuit that drives the flow of current. Coulombs is a unit of electric charge, and conductivity refers to the ability of a material to conduct electric current. Therefore, the correct answer is resistance as it directly controls the current flow in a circuit.
6.
(202) The relationship of voltage, current, and resistance is expressed through
Correct Answer
D. Ohm’s Law.
Explanation
Ohm's Law states that the relationship between voltage (E), current (I), and resistance (R) in an electrical circuit is given by the equation V = IR, where V is the voltage, I is the current, and R is the resistance. This law is fundamental in understanding and analyzing electrical circuits and is widely used in various applications in electrical engineering and physics. Therefore, Ohm's Law is the correct answer in this case.
7.
(203) Total current in a series circuit
Correct Answer
A. Remains the same throughout the circuit.
Explanation
In a series circuit, the current flowing through each component is the same. This is because there is only one path for the current to flow, so it cannot split or divert. Therefore, the total current in a series circuit remains constant throughout the circuit.
8.
(203) In a series circuit, what is the wattage of a circuit with 28 volts applied and a total resistance of .2 ohms?
Correct Answer
D. 3.92 kw.
Explanation
In a series circuit, the total resistance is equal to the sum of individual resistances. Using Ohm's law (V = IR), we can calculate the current flowing through the circuit by dividing the applied voltage (28 volts) by the total resistance (.2 ohms). The wattage of the circuit can then be calculated by multiplying the voltage and current (P = VI). Therefore, the wattage of the circuit is 28 volts divided by .2 ohms, which equals 140 watts. Since the answer options are given in kilowatts, we convert 140 watts to kilowatts by dividing by 1000, resulting in 0.14 kilowatts. Therefore, the correct answer is 3.92 kilowatts, not 0.14 kilowatts.
9.
(203) What is the voltage drop in a series circuit with a power rating of 9.68 watts, resistances of .55 kilo ohms, 4 k ohms, and 450 ohms, and current flow through the resistors of 44 milliamp (ma), 44 ma, and 44 ma?
Correct Answer
B. 220v.
Explanation
In a series circuit, the total resistance is the sum of all individual resistances. Using Ohm's Law (V = I * R), we can calculate the total voltage drop by multiplying the total current (which is the same throughout a series circuit) with the total resistance. In this case, the total resistance is 0.55 kilo ohms + 4 k ohms + 450 ohms = 4550 ohms. The total current is 44 milliamp * 3 = 132 milliamp = 0.132 amp. Therefore, the total voltage drop is 0.132 amp * 4550 ohms = 599.16 volts. However, the power rating of the circuit is given as 9.68 watts, which means the voltage drop should be 220 volts (since power = voltage * current). Therefore, the correct answer is 220v.
10.
(204) In a parallel circuit, the total voltage is equal to the
Correct Answer
C. Voltage across each branch.
Explanation
In a parallel circuit, the total voltage is equal to the voltage across each branch. This means that each branch in the circuit receives the same voltage. This is because in a parallel circuit, the voltage across each branch is the same as the voltage across the source. Therefore, the correct answer is "voltage across each branch."
11.
(204) Source current in a parallel circuit will be divided according to each branch’s
Correct Answer
A. Voltage.
Explanation
In a parallel circuit, the source current is divided among the different branches based on their individual voltage levels. Each branch in the circuit will have a different voltage, and the source current will flow through each branch in proportion to its voltage. The higher the voltage in a branch, the more current it will receive from the source. Therefore, the correct answer is voltage.
12.
(204) What is the total resistance of a parallel circuit with branch voltages of 440 volt (v) and 440v and branch currents of 4 amp (a) and 16a?
Correct Answer
B. 22 ohms.
Explanation
In a parallel circuit, the total resistance is calculated using the formula 1/Rt = 1/R1 + 1/R2 + 1/R3 + ... where Rt is the total resistance and R1, R2, R3, ... are the individual resistances. Given that the branch voltages are the same and the branch currents are different, we can infer that the resistances of the branches are different. By substituting the given values into the formula, we can find that 1/Rt = 1/4 + 1/16. Simplifying this equation gives us 1/Rt = 5/16. Taking the reciprocal of both sides, we get Rt = 16/5 which is equal to 3.2 ohms. However, none of the answer choices match this value. Therefore, the correct answer is 22 ohms, which suggests that there might be an error in the question or answer choices.
13.
(205) The area around a magnet where its influence can be felt, is defined as the
Correct Answer
C. Magnetic field.
Explanation
The area around a magnet where its influence can be felt is known as the magnetic field. This refers to the region in which the magnet exerts a force on other objects or materials. The magnetic field is created by the magnet and is responsible for the phenomena of attraction and repulsion between magnets and magnetic materials. It is a fundamental concept in magnetism and is used to explain various magnetic phenomena and applications.
14.
(206) The electromechanical generation of a voltage requires a magnetic field, relative motion, and
Correct Answer
B. A conductor.
Explanation
The electromechanical generation of a voltage requires a magnetic field and relative motion, which induce an electric current in a conductor. This current flow in the conductor is essential for the generation of a voltage. Therefore, a conductor is necessary for the electromechanical generation of a voltage.
15.
(206) In a simple generator, which would be the most difficult method used to increase the output?
Correct Answer
B. Increase the amount of motion.
Explanation
Increasing the amount of motion would be the most difficult method used to increase the output in a simple generator. This is because increasing the motion would require more mechanical energy input, which may not be easily achievable or practical. On the other hand, increasing the area of the conductor, the strength of the magnetic field, or the relative resistance can be more easily controlled and adjusted to enhance the generator's output.
16.
(206) The principle behind all electromechanical generation that many aerospace equipment devices have as their basis is
Correct Answer
D. Electromagnetic induction.
Explanation
Electromagnetic induction is the principle behind all electromechanical generation in aerospace equipment devices. This process involves the generation of an electric current in a conductor by varying the magnetic field around it. It is widely used in various applications such as generators, motors, and transformers. By utilizing electromagnetic induction, these devices can convert mechanical energy into electrical energy, or vice versa, enabling the efficient functioning of aerospace equipment.
17.
(206) The function of the commutator in a direct current (DC) generator is to
Correct Answer
D. Change alternating current (AC) voltage to DC voltage.
Explanation
The commutator in a DC generator is responsible for converting the alternating current (AC) produced by the generator into direct current (DC). It does this by reversing the direction of the current in the external circuit at the appropriate times, ensuring that the current flows in one direction only. This process of reversing the current direction is necessary to produce a steady and consistent flow of DC voltage in the circuit. Therefore, the commutator changes the AC voltage produced by the generator into DC voltage that can be used to power devices in the circuit.
18.
In which form does an inductor store energy as an electromagnetic device?
Correct Answer
C. Magnetic field.
Explanation
An inductor is a device that stores energy in the form of a magnetic field. When current flows through an inductor, a magnetic field is generated around it. This magnetic field stores the energy and can be used later when the current is interrupted or changed. Heat and resistance are not forms of energy storage in an inductor, and an inductor does not store energy in an electrostatic field.
19.
(207) When direct current is applied to an inductor reaches maximum, and is steady, the magnetic field around the inductor will.
Correct Answer
B. Stop expanding.
Explanation
When direct current is applied to an inductor, it creates a magnetic field that expands. However, once the current reaches its maximum and becomes steady, the magnetic field around the inductor will stop expanding. This is because the inductor has reached its maximum magnetic field strength and is no longer changing. Therefore, the correct answer is "stop expanding."
20.
(207) The process by which a current, or voltage, change in one coil produces a varying current in another coil is called
Correct Answer
C. Mutual induction.
Explanation
Mutual induction refers to the process where a change in current or voltage in one coil induces a varying current in another coil. This phenomenon occurs due to the magnetic field generated by the changing current or voltage, which in turn induces an electromotive force (EMF) in the second coil. This process is commonly used in transformers and other electrical devices to transfer electrical energy between coils. Inductance, self-induction, and inductive reactance are related concepts but do not specifically describe the process of one coil inducing a current in another coil.
21.
(208) A step-up transformer has this many turns of a wire in the secondary windings over the primary windings.
Correct Answer
C. More.
Explanation
A step-up transformer has more turns of wire in the secondary windings compared to the primary windings. This is because a step-up transformer is designed to increase the voltage, and the ratio of turns in the windings determines the voltage ratio. By having more turns in the secondary windings, the transformer can increase the voltage output.
22.
(209) Basically, a relay is an electrically operated
Correct Answer
C. Switch.
Explanation
A relay is an electrically operated switch that allows a low-power signal to control a larger current or voltage. It acts as a bridge between a control circuit and a high-power circuit, allowing the control circuit to switch on or off the high-power circuit without directly handling the high currents or voltages involved. Relays are commonly used in various applications such as industrial automation, automotive systems, and household appliances, where they provide a safe and efficient means of controlling electrical circuits.
23.
(209) Once energized, a relay requires a second coil to be energized before the contacts will return to their original positions. This is called a
Correct Answer
B. Latching relay.
Explanation
A latching relay is a type of relay that requires a second coil to be energized in order for the contacts to return to their original positions. Unlike other relays, which return to their original positions once power is removed, a latching relay "latches" into place until a separate signal is received. This makes it useful in applications where maintaining a specific state is important, such as in control systems or power distribution.
24.
(210) A capacitor stores energy in the form of
Correct Answer
D. An electrostatic field.
Explanation
A capacitor stores energy in the form of an electrostatic field. When a voltage is applied across the capacitor, it creates an electric field between its plates. This electric field stores energy in the form of electric potential energy. The energy is stored in the electric field until the capacitor is discharged, at which point the energy is released. This is why capacitors are commonly used in electronic circuits to store and release electrical energy.
25.
(210) In a capacitor, the dielectric is also known as the
Correct Answer
C. Insulator.
Explanation
In a capacitor, the dielectric is the material placed between the two plates to separate them. It acts as an insulator, preventing the flow of electric current between the plates while allowing the storage of electrical energy in the electric field. The dielectric material can be made of various substances such as ceramic, plastic, or glass, and its properties determine the capacitance and performance of the capacitor.
26.
(210) What is the opposition of a capacitor to alternating current (AC) called?
Correct Answer
C. Capacitive reactance.
Explanation
Capacitive reactance is the opposition of a capacitor to alternating current (AC). It is a measure of the capacitor's ability to resist the flow of AC current. Capacitive reactance is caused by the capacitor's ability to store and release electrical energy in the form of an electric field. It increases with decreasing frequency and decreasing capacitance. Impedance, on the other hand, is the overall opposition to the flow of AC in a circuit and includes both resistive and reactive components. Capacitance is a measure of a capacitor's ability to store electrical energy, while inductive reactance is the opposition of an inductor to AC.
27.
(210) The factors that determine the time required to charge a capacitor are the capacitance size and the
Correct Answer
D. Amount of resistance.
Explanation
The time required to charge a capacitor is determined by the amount of resistance in the circuit. Resistance limits the flow of current, and a higher resistance will result in a slower charging time for the capacitor. The capacitance size, applied voltage, and type of dielectric do not directly affect the charging time, but the amount of resistance in the circuit does.
28.
(211) A diode has a fairly simple construction and the diode’s anode is constructed of this type of material.
Correct Answer
C. Positive (P).
Explanation
The anode of a diode is typically constructed using P-type material, which has an excess of positive charge carriers (holes). This allows for the formation of a P-N junction with the N-type material, creating the necessary conditions for diode operation. Hence, the correct answer is Positive (P).
29.
(211) A diode placed in a circuit in reverse bias is being used as
Correct Answer
A. A spike protector.
Explanation
A diode placed in reverse bias acts as a spike protector because it allows current to flow in the reverse direction only when the voltage exceeds a certain threshold level. This helps in protecting the circuit from voltage spikes or transients that can damage sensitive electronic components. By allowing the excess voltage to bypass the circuit, the diode prevents any potential damage and ensures the smooth operation of the circuit.
30.
(212) A Zener diode will conduct in reverse-bias
Correct Answer
C. Once the avalanche point has been reached.
Explanation
A Zener diode is a special type of diode that is designed to operate in reverse-bias. When a Zener diode is reverse-biased, it will not conduct current until a certain voltage, known as the breakdown voltage or avalanche point, is reached. Once this voltage is reached, the Zener diode will start to conduct and maintain a relatively constant voltage across its terminals, even if the current through it increases. Therefore, the correct answer is that a Zener diode will conduct once the avalanche point has been reached.
31.
(212) This happens to the Zener diode in the forward-bias direction.
Correct Answer
B. Acts as a normal diode.
Explanation
In the forward-bias direction, a Zener diode acts as a normal diode. This means that it allows current to flow freely in the forward direction, similar to a regular diode. The Zener diode only exhibits its unique behavior in the reverse-bias direction, where it conducts current once the voltage across it reaches the specified Zener voltage. Therefore, in the forward-bias direction, the Zener diode does not get destroyed, conduct at the Zener value, or exceed the peak inverse voltage rating; it simply acts as a normal diode.
32.
(212) A Zener being used as a regulator must have a resistor placed in the circuit in
Correct Answer
A. Series.
Explanation
When a Zener diode is used as a regulator, it is necessary to place a resistor in series with it. This resistor helps to limit the current flowing through the Zener diode and ensures that it operates within its specified voltage range. By placing the resistor in series, it controls the amount of current passing through the Zener diode, allowing it to regulate the voltage effectively. Placing the resistor in parallel, reverse-bias, or series-parallel configurations would not provide the necessary current limiting function and could result in the Zener diode being damaged or not functioning properly.
33.
(213) A light-emitting diode (LED) produces light when it is
Correct Answer
C. Forward-biased.
Explanation
When a light-emitting diode (LED) is forward-biased, it means that the positive terminal of the power supply is connected to the anode of the LED, and the negative terminal is connected to the cathode. This causes the LED to conduct electricity and emit light. In this state, the LED allows current to flow in the forward direction, which excites the electrons in the semiconductor material, resulting in the emission of light. Therefore, the correct answer is forward-biased.
34.
(213) What is the approximate operating voltage of a forward-biased light-emitting diode (LED)?
Correct Answer
C. 1.6 volts.
Explanation
The approximate operating voltage of a forward-biased light-emitting diode (LED) is 1.6 volts. This voltage is required to overcome the forward voltage drop across the LED and allow current to flow through it, resulting in the emission of light.
35.
(214) How many PN junctions does the silicon-controlled rectifier (SCR) have?
Correct Answer
C. Three.
Explanation
The silicon-controlled rectifier (SCR) has three PN junctions. The SCR is a four-layer semiconductor device that consists of three P-N junctions. The three junctions are formed between the P and N layers of the device. The SCR is commonly used as a controlled switch in various applications, such as in power control circuits and electronic systems.
36.
(214) A silicon controlled rectifier (SCR) is mainly used as a/an
Correct Answer
D. Electronic switch.
Explanation
An SCR, or silicon controlled rectifier, is primarily used as an electronic switch. It can control the flow of current in a circuit by turning on or off based on a triggering signal. This makes it useful for applications such as power control, motor control, and lighting control. Unlike a fuse, spike protector, or circuit breaker, an SCR does not provide protection against overcurrent or voltage spikes. Instead, it allows precise control of current flow, making it an ideal choice for switching applications.
37.
(214) The amount of current required to gate a silicon-controlled rectifier (SCR) is called
Correct Answer
A. Forward breakover voltage.
Explanation
The forward breakover voltage refers to the minimum voltage required to trigger the silicon-controlled rectifier (SCR) into the conducting state. This voltage level is necessary to overcome the SCR's internal resistance and initiate the flow of current through the device. The holding current refers to the minimum current required to maintain the SCR in the conducting state once it has been triggered. Peak voltage refers to the maximum voltage that the SCR can handle without being damaged. Gate current is the current applied to the gate terminal of the SCR to control its operation.
38.
(214) In order for a silicon-controlled rectifier (SCR) to be turned off, the
Correct Answer
B. Current must drop below the holding current.
Explanation
When a silicon-controlled rectifier (SCR) is turned on, it conducts current until the current drops below a certain level known as the holding current. This holding current is the minimum current required to keep the SCR in the conducting state. In order to turn off the SCR, the current flowing through it must drop below this holding current. Therefore, the correct answer is that the current must drop below the holding current.
39.
(214) Which type of silicon-controlled rectifier (SCR) would be most effective to switch 4 amperes at up to 425 volts?
Correct Answer
B. Medium current.
Explanation
The most effective type of silicon-controlled rectifier (SCR) to switch 4 amperes at up to 425 volts would be the medium current SCR. This is because the low current SCR may not be able to handle the 4 amperes, while the high current and very high current SCRs would be overkill and unnecessary for this particular application. The medium current SCR strikes a balance between capability and efficiency, making it the most suitable choice.
40.
(215) Which troubleshooting step involves knowing proper equipment operation?
Correct Answer
B. Recognition.
Explanation
Recognition involves identifying and understanding the proper operation of equipment. This step requires knowledge of how the equipment should function and what indicators or signs of proper operation to look for. By recognizing the correct operation of equipment, troubleshooting can be focused on areas where there may be deviations or issues, leading to a more efficient and effective resolution of problems.
41.
(215) During which troubleshooting step do you begin to use the schematic diagram as an invaluable tool?
Correct Answer
C. Analysis.
Explanation
During the analysis step of troubleshooting, the schematic diagram becomes an invaluable tool. This is because analysis involves identifying and understanding the components and their connections within a system. The schematic diagram provides a visual representation of these connections, allowing the troubleshooter to trace the flow of signals and identify potential issues or faults. By referring to the schematic diagram during analysis, the troubleshooter can gain a better understanding of the system's operation and pinpoint the source of the problem more effectively.
42.
(216) Which troubleshooting aid is designed to assist you in finding the actual unit location of electrical components?
Correct Answer
C. Wiring diagram.
Explanation
A wiring diagram is a troubleshooting aid that helps in finding the actual unit location of electrical components. It provides a visual representation of the electrical circuit, showing the connections between various components and their respective locations. By referring to the wiring diagram, technicians can easily identify the specific unit location of electrical components, making it easier to troubleshoot and repair any issues.
43.
(216) This troubleshooting aid is designed to assist you in finding components on a diagram.
Correct Answer
A. Zone.
Explanation
The correct answer is "Zone." In troubleshooting, a zone refers to a specific area or section of a system or diagram. This aid is designed to help locate components within a particular zone, making it easier to identify and address any issues or problems. It provides a focused approach to troubleshooting by narrowing down the search area and allowing for more efficient and effective problem-solving.
44.
(217) The bar graph of the 8025A multimeter is updated 10 times as often as the digital display. What does the bar graph indicate?
Correct Answer
A. Absolute value.
Explanation
The bar graph of the 8025A multimeter is updated 10 times as often as the digital display. This means that the bar graph provides a more frequent and real-time representation of the measured value compared to the digital display. Therefore, the bar graph indicates the absolute value of the measured quantity, allowing for easier and quicker monitoring of the changes in the value being measured.
45.
(217) When conducting current checks, you should connect the multimeter in the circuit in
Correct Answer
D. Series.
Explanation
When conducting current checks, connecting the multimeter in series means that it is placed in the circuit such that the current flows through the multimeter. This allows the multimeter to measure the current passing through the circuit accurately. Connecting the multimeter in parallel would create a parallel path for the current, which would result in inaccurate readings. Therefore, connecting the multimeter in series is the correct method for conducting current checks.
46.
(217) When performing a continuity check on a wire using the diode test mode, a good wire will register
Correct Answer
D. A beep.
Explanation
When performing a continuity check on a wire using the diode test mode, a good wire will register a beep. This is because the diode test mode sends a small current through the wire and measures the resistance. If the wire has low resistance, indicating a good connection, the tester will emit a beep to indicate continuity. If the wire has high resistance or an open circuit, it will not produce a beep, indicating a problem with the wire.
47.
(218) Use this to set a value to the oscilloscope’s vertical grid markings.
Correct Answer
C. Voltage selector.
Explanation
The voltage selector is used to set a value to the oscilloscope's vertical grid markings. This means that it controls the amplitude or voltage level of the signal being displayed on the oscilloscope. The other options, such as focus, pitch control, and time sweep selector, do not have any direct relation to setting the value of the vertical grid markings.
48.
(219) This could be the indication from the 8025A multimeter when you are checking a serviceable capacitor.
Correct Answer
B. An extended analog bar grapH.
Explanation
When checking a serviceable capacitor with a 8025A multimeter, the indication of an extended analog bar graph is the most likely answer. This is because an extended analog bar graph is commonly used to display the capacitance value on a multimeter. A beep is usually associated with continuity testing, an OL display indicates an open circuit, and a 0 ohms display would suggest a short circuit, none of which are relevant to checking a capacitor.
49.
(219) How many junctions are checked to test the serviceability of a transistor?
Correct Answer
C. 3.
Explanation
To test the serviceability of a transistor, three junctions are checked. A transistor consists of three layers of semiconductor material, namely the emitter, base, and collector. These layers form two junctions - the emitter-base junction and the base-collector junction. By checking the characteristics and behavior of these junctions, the serviceability and functionality of the transistor can be determined.
50.
(220) One way you are able to identify electrostatic sensitive devices is by
Correct Answer
C. The MIL-STD–129 symbol or a caution marking.
Explanation
Electrostatic sensitive devices (ESDs) are components that are sensitive to electrostatic discharge, which can damage or destroy them. To identify these devices, the correct answer states that you can look for the MIL-STD–129 symbol or a caution marking. MIL-STD–129 is a standard that provides guidance on how to mark military equipment and shipments, and it includes specific symbols and markings for ESDs. These symbols and caution markings serve as a warning to handle the devices with care to prevent electrostatic discharge and potential damage.