Aerospace Ground Equipment CDC Vol. 2

Resistance is used to control current flow in a circuit. It is a property of a material or component that opposes the flow of electric current. When resistance is increased, the current flow decreases, and when resistance is decreased, the current flow increases. This is achieved by using resistors in the circuit, which are designed to have a specific resistance value. By adjusting the resistance, the amount of current flowing through the circuit can be controlled.

A relay is an electrically operated switch. It is a device that allows a low-power signal to control a high-power circuit. When the relay receives an electrical signal, it activates an electromagnet which then opens or closes the switch contacts, allowing or interrupting the flow of current in the circuit. This makes it a versatile component used in various applications where a low-power control signal needs to control a high-power circuit.

Ohm's Law is the correct answer because it expresses the relationship between voltage (E), current (I), and resistance (C). According to Ohm's Law, the current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to the resistance of the conductor. This relationship is expressed by the equation I = E/C, where I is the current, E is the voltage, and C is the resistance. Ohm's Law is a fundamental principle in electrical circuits and is used to calculate and understand the behavior of electrical systems.

The magnetic field of an electromagnet can be varied by changing the type of core, the number of turns in the coil, and the amount of current through the coil. The type of core affects the strength of the magnetic field, with different materials having different magnetic properties. Increasing the number of turns in the coil increases the magnetic field strength, as each turn contributes to the overall field. Finally, increasing the amount of current flowing through the coil increases the strength of the magnetic field according to Ampere's law. Therefore, all of the above options can be used to vary the magnetic field of an electromagnet.

A magnetic field refers to the area around a magnet where its influence can be felt. It is a region in which magnetic forces are exerted on other objects or magnets. This field is responsible for the attraction or repulsion between magnets and the interaction between magnets and magnetic materials. Therefore, the correct answer is magnetic field.

The systematic method is the best method of troubleshooting because it involves a step-by-step approach to identify and solve problems. It allows for a logical and organized process, ensuring that all possible causes are considered and systematically eliminated until the root cause is found. This method minimizes the chances of missing any important steps or overlooking potential solutions, leading to more efficient and effective troubleshooting.

Residual magnetism refers to the magnetism that remains in a material even after the magnetizing force has been removed. This phenomenon occurs when the magnetic domains within the material align in a specific direction due to the applied magnetic field. The alignment of these domains creates a net magnetic field within the material, resulting in residual magnetism.

Current is defined as the flow or drift of electrons through a conductor in the same direction at the same time. It is the movement of electric charge, typically measured in amperes, and is responsible for the transfer of energy and the operation of electrical devices. Conductivity refers to the ability of a material to conduct electric current, voltage is the potential difference between two points in a circuit, and valence refers to the combining capacity of an atom.

Voltage is the correct answer because potential difference is the measure of the electrical force that pushes the free electrons in a circuit. It is the force that causes the flow of electrons, also known as electric current. Conductivity refers to the ability of a material to conduct electricity, while valence is a property of atoms.

An atom with eight electrons in its outermost shell is said to be stable. This is because the outermost shell, also known as the valence shell, is considered complete when it contains eight electrons. This configuration is known as the octet rule and is commonly observed in noble gases, which have full outer shells and are therefore very stable. In contrast, atoms with fewer or more than eight electrons in their outermost shell tend to be reactive and less stable, as they seek to gain, lose, or share electrons to achieve a stable configuration.

Electromagnetic induction is the principle behind all electromechanical generation. This principle states that when a conductor moves through a magnetic field or when there is a change in the magnetic field around a conductor, an electromotive force (EMF) is induced in the conductor. This induced EMF can then be used to generate electricity in various electromechanical devices such as generators and transformers. Electromagnetic induction is a fundamental concept in physics and plays a crucial role in the functioning of many electrical power systems.

The term "dielectric" is used to refer to insulators. Insulators are materials that do not conduct electricity well and have high resistance to the flow of electric current. Dielectrics are commonly used in capacitors and other electrical devices to store and distribute electrical energy. They are characterized by their ability to store electric charge when an electric field is applied to them. Unlike conductors, which allow the flow of electrons, dielectrics prevent the flow of electrons and act as an electrical insulator.

In order to generate a voltage electromechanically, a conductor is necessary. A conductor is a material that allows the flow of electric current. When there is relative motion between a magnetic field and a conductor, it induces a voltage in the conductor according to Faraday's law of electromagnetic induction. This voltage can then be used to create an electric current in a complete circuit, which can power a load. Therefore, a conductor is an essential component for the electromechanical generation of a voltage.

A good conductor requires a small number of valence electrons to easily move through the material. This allows for the efficient flow of electric current. Therefore, having only 3 valence electrons would make a material a good conductor as it would have less resistance to the movement of electrons.

The winding of a transformer that is connected to a power source is known as the primary winding. This is because the primary winding is responsible for receiving the electrical energy from the power source and transferring it to the secondary winding. The primary winding typically has a higher number of turns compared to the secondary winding, allowing it to step up or step down the voltage as required by the transformer.

The Silicon Controlled Rectifier (SCR) has three PN junctions. This semiconductor device consists of three layers of alternating P-type and N-type materials. The two outer layers are P-type, and the middle layer is N-type. The junctions between these layers form the three PN junctions. These junctions play a crucial role in the operation of the SCR, allowing it to control the flow of electric current effectively.

When a soldering iron tip becomes pitted or worn, it can affect the quality of solder joints. Tinning the tip involves coating it with a thin layer of solder, which helps to improve heat transfer and prevent oxidation. This process restores the tip's functionality and extends its lifespan. Therefore, the correct answer is tinned.

In a capacitor, the dielectric is the insulator. The dielectric is a material that is placed between the plates of a capacitor to increase its capacitance. It acts as an electrical insulator, preventing the flow of direct current between the plates while allowing the storage of electric charge. The dielectric material can be made from various substances such as ceramic, plastic, or paper. Its main purpose is to reduce the electric field strength between the plates, thereby increasing the capacitance of the capacitor.

Permeability refers to the ability of a material to allow lines of force to pass through it. It is a measure of how easily magnetic flux can pass through a substance. Materials with high permeability allow a greater amount of magnetic flux to pass through, while materials with low permeability impede the flow of magnetic flux. Permeability is an important property in electromagnetism and is used to describe the behavior of magnetic materials in the presence of a magnetic field.

In the secondary windings of a step-up transformer, the turns of wire are more than the turns of wire in the primary windings. This is because a step-up transformer is designed to increase the voltage from the primary side to the secondary side. By having more turns of wire in the secondary windings, the transformer can effectively step up the voltage.

Every atom must contain electrons and protons. Electrons are negatively charged particles that orbit around the nucleus of an atom, while protons are positively charged particles located in the nucleus. These two particles are essential for the stability and structure of an atom. Neutrons, on the other hand, are neutral particles and are not required in every atom, although they can be present in some atoms to provide stability.

The commutator in a DC generator is responsible for converting the alternating current (AC) produced by the generator into direct current (DC) voltage. It achieves this by reversing the direction of the current in the external circuit at the appropriate moment, ensuring that the output voltage remains constant and flows in a single direction. This process of commutation allows the generator to produce a steady and continuous flow of DC voltage, which is essential for many electrical applications.

Mutual induction is the process by which a current change in one coil induces a voltage in another coil. This occurs when the magnetic field produced by the changing current in one coil cuts through the turns of the second coil, causing a voltage to be induced. This phenomenon is commonly used in transformers, where mutual induction is utilized to transfer electrical energy from one coil to another. Inductance refers to the property of a coil to oppose changes in current, while self-induction is the induction of a voltage in the same coil due to changes in current.

A relay that, once energized, requires a second coil to be energized before the contacts will return to their original positions is called a latching relay. This type of relay "latches" or holds its position until a separate signal is received to release it. It is commonly used in applications where it is necessary to maintain a specific state until a reset signal is received. Unlike other relays that return to their original position once the power is removed, a latching relay remains in its last position until specifically reset.

The correct answer is to remove the insulation. When soldering a conductor, the first step is to remove the insulation from the wire. This is necessary to expose the bare metal surface of the conductor, which allows for proper soldering. Insulation can hinder the flow of heat and prevent the solder from bonding effectively. By removing the insulation, the bare wire is ready to be heated and soldered to create a strong and reliable connection.

The best method of repairing a lifted circuit track on a PCB is to replace it with insulated wire. This is because insulated wire provides better insulation and protection against short circuits compared to bare wire. Additionally, using insulated wire helps to maintain the integrity of the circuit and prevent further damage. Bonding or gluing the lifted circuit track may not provide a secure and reliable connection, and it may not provide the necessary insulation.

An inductor is called a reactive device because it stores energy in its magnetic field when current flows through it. This stored energy is then returned to the circuit when the current changes or is interrupted. Unlike resistive devices, which dissipate energy in the form of heat, inductors do not consume power but rather store and release it. Therefore, the term "reactive" accurately describes the behavior of an inductor in a circuit.

The correct answer is "wire touches the bottom". This means that the wire is inserted into the solder cup until it makes contact with the bottom of the cup. This ensures a secure connection and proper conductivity between the wire and the cup.

When soldering flat perforated terminals, the conductor is connected to the terminal using a 180 degree wrap. This means that the conductor is wrapped around the terminal in a half-circle shape, creating a secure and strong connection. This wrapping method ensures that the conductor is tightly secured to the terminal, preventing any loosening or disconnection that could cause electrical issues. Additionally, the 180 degree wrap allows for maximum surface contact between the conductor and the terminal, optimizing the flow of current and minimizing resistance.

The anode of a diode is typically made of a positive material. In a diode, current can only flow in one direction, from the anode to the cathode. The anode is positively charged, while the cathode is negatively charged. When a forward bias voltage is applied, the positive material in the anode attracts the negatively charged electrons, allowing current to flow through the diode. Therefore, the anode is made of positive material to facilitate the flow of current in the desired direction.

LEDs (Light Emitting Diodes) are semiconductor devices that emit light when an electric current passes through them. They have a specific forward voltage drop, which is the approximate voltage required for them to function properly. The approximate operating voltage of a LED is commonly around 1.6 volts. This voltage may vary slightly depending on the specific type and color of the LED, but 1.6 volts is a typical value.

Electrostatic sensitive devices are marked with the MIL-STD-129 symbol or a caution marking. This marking is used to indicate that the device is sensitive to electrostatic discharge and proper precautions need to be taken while handling it. The MIL-STD-129 symbol or caution marking serves as a visual reminder for individuals to use appropriate grounding techniques and anti-static measures to prevent damage to the device.

When a diode is placed in reverse bias, it allows only a very small amount of current to flow in the opposite direction. This makes it useful as a spike protector in a circuit. When a voltage spike occurs, the diode acts as a barrier, preventing the spike from damaging the rest of the circuit. Therefore, the correct answer is a spike protector.

A heat sink is a device used to dissipate heat and prevent overheating of electronic components. When soldering, excessive heat can be generated, which can potentially damage not only the component being soldered but also other nearby components in the circuit. By using a heat sink, the heat is efficiently transferred away from the soldered area, protecting both the soldered component and the surrounding components from heat damage.

A transformer is an electrical device that is used to transfer electrical energy between two or more circuits through electromagnetic induction. It works by changing the voltage and current levels of the input electrical energy to the desired levels in the output circuit. However, the transformer does not change the power. Power is the product of voltage and current, and in a transformer, the power in the input circuit is equal to the power in the output circuit. Therefore, the correct answer is power.

Biasing refers to the process of applying a DC voltage to a diode or transistor in order to establish a desired operating point. By applying a bias voltage, the depletion region of a diode can be expanded or contracted, allowing or preventing the flow of current through the diode. This is essential for controlling the behavior of the diode and ensuring it operates within its desired range. Therefore, biasing is the correct term for expanding or contracting the depletion region of a diode.

The reference designation index is designed to aid you if you see an unfamiliar symbol. It provides a list of symbols used in a schematic or wiring diagram along with their corresponding reference designations, helping you identify and understand the meaning of the symbols. This can be particularly useful when troubleshooting electrical or electronic systems, as it allows you to quickly locate and interpret unfamiliar symbols, enabling effective problem-solving.

Zones are a troubleshooting aid that are designed to aid in finding components on a diagram. They divide a diagram into different sections or areas, making it easier to locate specific components or areas of interest. By using zones, technicians can quickly identify and navigate to the relevant parts of a diagram, saving time and effort in troubleshooting and repair tasks.

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 two plates. This electric field causes the accumulation of positive and negative charges on the plates, creating an electrostatic field. The energy is stored in this field, and when the capacitor is discharged, the energy is released back into the circuit. This is why capacitors are commonly used in electronic devices for energy storage and power regulation.

Once the avalanche point has been reached, a zener diode will conduct in reverse bias. The avalanche breakdown occurs when the voltage across the diode exceeds a certain threshold, causing a rapid increase in current flow. At this point, the diode enters the breakdown region and starts conducting in reverse bias. Therefore, once the avalanche point is reached, the zener diode will conduct.

When the current flowing through an SCR drops below the holding current, the SCR will turn off. The holding current is the minimum current required to maintain conduction in the SCR once it has been triggered. Therefore, if the current drops below this threshold, the SCR will stop conducting and turn off. This is the condition that needs to be met for the SCR to be turned off.

In a series circuit, the current is the same throughout all components. This means that the total current in the circuit is equal to the current through one component. Therefore, the correct answer is "current through one component".

Capacitive reactance is the opposition that a capacitor exhibits to the flow of alternating current (AC). It is caused by the storage and release of electrical energy in the capacitor. When AC is applied to a capacitor, the capacitor charges and discharges, resulting in a phase shift between the voltage and current. This opposition is known as capacitive reactance, and it is measured in ohms. It is the opposite of inductive reactance, which is the opposition exhibited by an inductor to AC. Impedance, on the other hand, is the overall opposition to the flow of AC in a circuit and includes both resistance and reactance. Capacitance refers to the ability of a capacitor to store electrical energy.

In a parallel circuit, the current flowing through each branch is determined by the resistance of that branch. This is because the total current entering the parallel circuit is divided among the different branches based on their resistance values. The branch with a lower resistance will allow more current to flow through it, while the branch with a higher resistance will allow less current to flow through it. Therefore, the statement that the source current in a parallel circuit will be divided according to resistances is correct.

During the analysis step of troubleshooting, you try to determine which system could be causing the malfunction by gathering information, examining symptoms, and identifying potential causes. This involves reviewing any available logs, conducting tests, and analyzing data to narrow down the possible sources of the problem. By carefully analyzing the situation, you can gain insights into the underlying issues and make informed decisions about the next steps in the troubleshooting process.

Recognition is the troubleshooting step that is done by knowing proper equipment operation. This step involves identifying the symptoms and issues related to the equipment based on the knowledge of how it should operate. By recognizing the normal operation of the equipment, it becomes easier to identify any deviations or abnormalities that may indicate a problem. This step is crucial in the troubleshooting process as it helps in narrowing down the potential causes of the issue and determining the appropriate course of action.

An inductor stores energy in the form of a magnetic field. When current flows through an inductor, a magnetic field is created around it. This magnetic field stores energy, which can be released when the current is interrupted or changed. This property of inductors is utilized in various applications such as transformers, motors, and generators, where the stored energy in the magnetic field is converted into useful work.

The wattage of a circuit can be calculated using the formula P = V^2 / R, where P is the power in watts, V is the voltage in volts, and R is the resistance in ohms. In this case, the voltage is 28 volts and the resistance is 0.2 ohms. Plugging these values into the formula, we get P = 28^2 / 0.2 = 784 / 0.2 = 3920 watts. Since the question asks for the wattage in kilowatts, we divide the result by 1000 to get 3.92 kilowatts.

When testing a transformer, an open coil reading on the 8025A multimeter will be indicated by "OL" which stands for "Open Loop". This means that there is no continuity or connection in the coil, indicating that the coil is open or broken. This reading suggests that there is a fault in the transformer and it needs to be repaired or replaced.

The forward breakover voltage refers to the minimum voltage required to trigger the SCR into conduction when a positive gate current is applied. It is the threshold voltage that must be exceeded for the SCR to start conducting current. The holding current, on the other hand, is the minimum current required to maintain conduction once the SCR has been triggered. Peak voltage refers to the maximum voltage that the SCR can withstand without breakdown. Gate current is the current that is applied to the gate terminal of the SCR to control its conduction.