2A652 CDC Volume 2: Test Questions On Aerospace Ground Equipment!

Resistance is used to control current flow in a circuit. Resistance is a measure of how much a material or component opposes the flow of electric current. It is measured in ohms (Ω). When resistance is increased in a circuit, it limits the amount of current that can flow through it. Conversely, when resistance is decreased, more current can flow. Therefore, by adjusting the resistance in a circuit, the current flow can be controlled.

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 magnetic permeability, which determines how easily the magnetic field lines pass through the core material. Increasing the number of turns in the coil increases the strength of the magnetic 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 these factors 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 the region in which magnetic forces are exerted on other objects or magnets. Magnetic fields are created by moving electric charges, such as the flow of current in a wire or the movement of electrons within an atom. The strength and direction of the magnetic field are determined by the properties of the magnet and the distance from it.

Residual magnetism refers to the magnetism that remains in a material even after the magnetizing force has been removed. It occurs due to the alignment of magnetic domains within the material. This phenomenon is commonly observed in permanent magnets, where the alignment of the domains creates a magnetic field that persists even without an external magnetic field. Residual magnetism is important in various applications, such as in the operation of electric motors and generators.

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 that opens or closes the switch contacts. This allows the relay to control the flow of electricity in a circuit, making it an essential component in many electrical systems.

The systematic method is the best method of troubleshooting because it involves following a step-by-step approach to identify and solve problems. This method ensures that all possible causes are considered and tested systematically, leading to a more efficient and effective troubleshooting process. It helps to eliminate guesswork and reduces the chances of missing any potential solutions. By following a systematic approach, troubleshooting becomes more organized and structured, increasing the likelihood of finding the root cause of the problem and implementing the appropriate solution.

An atom with eight electrons in its outermost shell is said to be stable. This is because the octet rule states that atoms tend to gain, lose, or share electrons in order to achieve a full outer shell of eight electrons, which is the most stable configuration. Having a full outer shell allows the atom to have a lower energy state and be less likely to react with other atoms. Therefore, an atom with eight electrons in its outermost shell is considered stable.

Current is the correct answer because it refers to the flow or drift of electrons through a conductor in the same direction at the same time. Conductivity refers to the ability of a material to conduct electricity, voltage refers to the electric potential difference between two points, and valence refers to the combining power of an element.

In a series circuit, the current passing through each component is the same. To calculate the current, we can use Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). In this case, the voltage is 24 volts and the resistance is 18 ohms. Therefore, the current through the resistor would be 24 volts divided by 18 ohms, which equals approximately 1.33 amps.

In order to generate a voltage electromechanically, a conductor is required. A conductor is a material that allows the flow of electric current. When the conductor moves relative to a magnetic field, it induces a voltage in the conductor through electromagnetic induction. This voltage can then be used to power a circuit or perform work. Therefore, a conductor is an essential component for the electromechanical generation of a voltage.

Voltage is the correct answer because it refers to the potential difference between two points in a circuit. It is the force that pushes free electrons and causes them to move. Conductivity refers to the ability of a material to conduct electricity, current refers to the flow of electric charge, and valence refers to the combining capacity of an element.

A reference designation index is a troubleshooting aid that helps when encountering unfamiliar symbols. It provides a comprehensive list of symbols used in a specific system or diagram, allowing the user to quickly identify and understand the meaning of the symbol they are unfamiliar with. This index serves as a reference guide, enabling efficient troubleshooting and problem-solving by providing clear and concise explanations for each symbol used.

A good conductor requires only 3 valence electrons. Valence electrons are the electrons in the outermost energy level of an atom, and they are responsible for the atom's ability to form bonds and participate in chemical reactions. In the case of conductors, having fewer valence electrons allows for easier movement of electrons, which is necessary for the material to conduct electricity effectively. Therefore, a material with 3 valence electrons would be more likely to be a good conductor compared to materials with 4, 5, or 6 valence electrons.

The term "dielectric" is used to refer to insulators. Insulators are materials that do not conduct electricity easily and have high resistance to the flow of electric current. They are commonly used to separate conductive materials and prevent the flow of electricity between them. Dielectrics are often used in capacitors, where they store electrical energy by creating an electric field. Unlike conductors, which allow the free flow of electrons, insulators keep electrons tightly bound to their atoms, limiting the movement of charge.

When a soldering iron tip becomes pitted or worn, it can affect the quality of solder joints. To address this issue, the tip should be redressed using a flat, fine single-cut file. However, after redressing, the tip should also be tinned. Tinning refers to the process of coating the tip with a thin layer of solder. This helps to prevent oxidation and improves heat transfer during soldering. Therefore, the correct answer is "tinned".

Electromagnetic induction is the principle behind all electromechanical generation. This process involves the generation of electric current in a conductor by varying the magnetic field around it. When a conductor is exposed to a changing magnetic field, it induces a voltage, which in turn produces an electric current. This phenomenon is used in various electrical generators, such as turbines, to convert mechanical energy into electrical energy. Therefore, electromagnetic induction is the correct principle behind electromechanical generation.

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 input power from the source and transferring it to the secondary winding, which then delivers the transformed output power. The primary winding typically has a higher number of turns compared to the secondary winding in order to step up or step down the voltage as required by the transformer.

In a capacitor, the dielectric is the insulator. The dielectric is a non-conductive material that is placed between the two plates of the capacitor to prevent the flow of electric current between them. It helps to increase the capacitance of the capacitor by storing more electric charge. The dielectric material can be made of various substances such as ceramic, plastic, or paper. It acts as a barrier, allowing the electric field to pass through but blocking the flow of electrons.

A diode placed in reverse bias acts as a spike protector because it allows current to flow only when the voltage across it exceeds a certain threshold, known as the breakdown voltage. In this configuration, the diode prevents voltage spikes by diverting excessive voltage away from sensitive components in the circuit. When a voltage spike occurs, the diode conducts and provides a low resistance path for the excess voltage, protecting the circuit from potential damage.

Zones are a troubleshooting aid designed to aid in finding components on a diagram. Zones divide a diagram into specific areas or sections, making it easier to locate and identify components. By using zones, technicians can quickly navigate the diagram and pinpoint the specific area where a component is located, simplifying the troubleshooting process.

Mutual induction is the process in which a current change in one coil induces a voltage in another coil. This occurs when the magnetic field created by the changing current in the first coil passes through the second coil, causing a voltage to be induced. This phenomenon is commonly used in transformers and is the basis for the operation of many electrical devices. Inductance refers to the property of a coil to oppose changes in current, while self-induction specifically refers to the voltage induced in the same coil where the current is changing.

The best method of repairing a lifted circuit track on a printed circuit board (PCB) is to replace it with insulated wire. This is because insulated wire provides electrical insulation and prevents short circuits between adjacent tracks. It also ensures that the repaired circuit track is secure and reliable. Bonding or gluing the lifted circuit track may not provide the necessary electrical insulation, while replacing it with bare wire may increase the risk of short circuits. Therefore, replacing it with insulated wire is the most suitable option for repairing a lifted circuit track on a PCB.

Biasing refers to the process of applying a voltage or current to a device such as a diode in order to establish the desired operating conditions. In the case of a diode, biasing involves either expanding or contracting the depletion region, which is the region devoid of free charge carriers. This adjustment of the depletion region allows for controlling the flow of current through the diode, making it an essential aspect of diode operation. Therefore, the correct answer is biasing.

When a Light Emitting Diode (LED) is forward biased, it means that the positive terminal of the power supply is connected to the anode (the longer leg) of the LED, and the negative terminal is connected to the cathode (the shorter leg). In this configuration, current flows from the anode to the cathode, allowing the LED to produce light. This is because forward biasing creates a forward voltage across the LED, causing the electrons and holes to recombine and emit photons, resulting in the production of light.

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 is designed to "latch" or hold its state even after the initial signal is removed. It requires a separate signal or coil to reset the relay back to its original position. Latching relays are commonly used in applications where it is necessary to maintain a specific state until a reset signal is received.

A schematic is a visual representation of a system or process, showing the relationships between different components. It helps promote understanding by providing a clear and concise overview of how the system works. By using symbols and labels, a schematic allows technicians to easily identify and troubleshoot any issues that may arise. It provides a comprehensive view of the system's structure and connections, making it an effective troubleshooting aid for promoting understanding.

When performing a continuity check on a wire using the diode test mode, a good wire will register a beep. This indicates that there is a continuous path for the current to flow through the wire, confirming its connectivity. The beep is produced by the multimeter to signal the presence of a low resistance connection, indicating that the wire is intact and functioning properly.

An electrostatic sensitive device can be identified by looking for the MIL-STD-129 symbol or a caution marking on the package. This marking indicates that the device is sensitive to electrostatic discharge and proper precautions should be taken during handling and storage to prevent damage. The MIL-STD-129 symbol or caution marking is a standard way of alerting individuals to the sensitivity of the device and reminding them to handle it with care.

In a parallel circuit, the current will divide among the different branches based on the resistance of each branch. This is because the branch with lower resistance will allow more current to flow through it compared to the branch with higher resistance. Therefore, the statement that the source current in a parallel circuit will be divided according to resistances is correct.

In a parallel circuit, the total resistance is calculated using the formula 1/Rt = 1/R1 + 1/R2 + 1/R3 + ... In this case, we have two branches with different voltages and currents. To find the resistance of each branch, we can use Ohm's law: R = V/I. For the first branch, R1 = 440v/4a = 110 ohms. For the second branch, R2 = 440v/16a = 27.5 ohms. Adding the reciprocals of these resistances gives 1/Rt = 1/110 + 1/27.5. Simplifying this equation gives Rt = 22 ohms.

The approximate operating voltage of a Light Emitting Diode (LED) is 1.6 volts. LED is a semiconductor device that emits light when an electric current passes through it. It requires a specific voltage to function properly, and in the case of an LED, it is approximately 1.6 volts. This voltage is necessary to activate the LED and generate the desired light output.

A heat sink is a device used to dissipate heat and prevent overheating. In the context of soldering, a heat sink is used to prevent heat from damaging other components in the circuit. When soldering, excessive heat can cause damage to nearby components, such as melting or deforming them. By using a heat sink, the heat is directed away from these sensitive components, protecting them from potential damage. Therefore, the correct answer is to prevent heat from damaging other components in the circuit.

When soldering flat perforated terminals, a 180 degree wrap is used to connect the conductor to the terminal. This means that the conductor is wrapped around the terminal in a half-circle shape, ensuring a secure and reliable connection. The 180 degree wrap allows for maximum contact between the conductor and the terminal, minimizing the risk of a loose or weak connection.

In a series-parallel circuit, the total current remains the same throughout the parallel portion of the circuit. This means that the current flowing through each branch in the parallel portion is equal. However, in the series portion of the circuit, the current divides according to the component resistance. This means that the current flowing through each component in the series portion is different and depends on the resistance of that component. Therefore, the correct answer is that the total current in a series-parallel circuit remains the same throughout the parallel portion of the circuit and divides according to branch resistance in the series portion.

It is important to make sure that all electrostatic sensitive devices are properly marked. This helps to identify and differentiate them from other devices, ensuring that they are handled and treated appropriately to prevent any damage or malfunction caused by electrostatic discharge. Proper marking also helps in organizing and keeping track of these sensitive devices, making them easily identifiable for use in the correct manner.

A transformer is a device that is used to change the voltage of an alternating current (AC) electrical supply. It works based on the principle of electromagnetic induction. When an AC current flows through the primary coil of the transformer, it creates a changing magnetic field which induces a voltage in the secondary coil. This voltage can be higher or lower than the input voltage, depending on the turns ratio of the transformer. However, a transformer does not change the power of the electrical supply. Power is the product of voltage and current, and since the transformer only changes the voltage and not the current, the power remains constant.

A zener diode conducts in reverse bias once the avalanche point has been reached. The avalanche point is the point at which the reverse voltage across the diode is high enough to cause a breakdown in the diode's structure. Once this point is reached, the zener diode starts conducting in reverse bias and allows current to flow through it. This behavior is useful in voltage regulation applications, where the zener diode can maintain a constant voltage across a load by conducting excess current in reverse bias.

The Silicon Controlled Rectifier (SCR) has three PN junctions. A PN junction is formed when a P-type semiconductor material is joined with an N-type semiconductor material. In the case of an SCR, there are three layers of alternating P-type and N-type materials, resulting in three PN junctions. These junctions play a crucial role in the operation of the SCR, allowing it to control the flow of current in a circuit.

The correct answer is "wire touches the bottom". This means that the wire is inserted into the solder cup until it reaches the bottom. This is an important step in the soldering process as it ensures that the wire is securely connected to the cup and allows for proper electrical conductivity.

A capacitor stores energy in the form of an electrostatic field. When a voltage is applied across the capacitor, it causes a separation of charge, with one plate accumulating positive charge and the other accumulating negative charge. This separation of charge creates an electric field between the plates, which stores energy. The energy is released when the capacitor is discharged, as the charges flow back together and the electric field collapses. This stored energy can be used in various electronic circuits and devices.

The emitter-base junction of a transistor is forward biased during normal operation. This means that the emitter terminal is at a higher potential than the base terminal, allowing current to flow from the emitter to the base. This forward biasing is essential for the transistor to function properly and amplify signals. It helps in controlling the flow of current between the emitter and collector terminals, allowing the transistor to act as a switch or amplifier in electronic circuits.

A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is a type of semiconductor device that has a gate which is not electrically connected to the rest of the device. The gate of a MOSFET is isolated from the channel by a thin layer of oxide, hence the name. This isolation allows for better control of the current flow through the device, making it a popular choice in many electronic applications. In contrast, an SCR (Silicon-Controlled Rectifier), JFET (Junction Field-Effect Transistor), and UJT (Unijunction Transistor) all have gates that are electrically connected to the rest of the device.

A good solder cup connection should exhibit the contour of the wire. This means that the solder should conform to the shape of the wire, indicating that there is good contact and adhesion between the wire and the solder. This ensures a strong and reliable connection, as it minimizes the risk of any loose or weak points in the solder joint.

In a series-parallel circuit, the total current is equal to the sum of the currents in each branch. Given that the series current is 6 amps and one branch current is 2 amps, the other branch current can be found by subtracting the series current from the total current. So, the other branch current is 6 amps - 2 amps = 4 amps. Therefore, the total current in the circuit is 2 amps + 4 amps = 6 amps.

Increasing the amount of motion would be the most difficult method to increase the output in a simple generator. This is because increasing the amount of motion would require additional mechanical energy input, which can be challenging to achieve. On the other hand, increasing the area of the conductor, the strength of the magnetic field, or the relative resistance can be relatively easier to accomplish and can result in a higher output.

In a series circuit, the current is the same throughout all components. This is because the current has only one path to flow through. Therefore, the total current in a series circuit is equal to the current through one component.

Careless soldering can be a major cause of shorts on printed circuit boards (PCB). When soldering is done improperly, it can result in solder bridges or solder splashes that connect two or more circuit tracks that should not be connected. This can cause a short circuit, leading to malfunction or damage of the PCB.

Capacitive reactance is the opposition of a capacitor to alternating current (AC). When AC voltage is applied to a capacitor, it charges and discharges, causing a phase shift between the voltage and current. This opposition to the flow of current is known as capacitive reactance. It is measured in ohms and is inversely proportional to the frequency of the AC signal. As the frequency increases, the capacitive reactance decreases, allowing more current to flow through the capacitor.

A FET (Field-Effect Transistor) is a component that uses voltage to control the size of the current flow channel. FETs have three terminals: source, gate, and drain. By applying a voltage to the gate terminal, the electric field generated controls the conductivity of the channel between the source and drain terminals. This voltage-controlled behavior of FETs makes them suitable for various applications, including amplification and switching in electronic circuits.

An SCR, or Silicon Controlled Rectifier, is primarily used as an electronic switch. It can control the flow of current in a circuit by acting as a gate that allows or blocks the current. This makes it useful in various applications where precise control of electrical power is required, such as in motor control, lighting control, and power supply regulation. Unlike a fuse, spike protection, or a circuit breaker, which are primarily used for protection against overcurrent or voltage spikes, an SCR is specifically designed to function as a switch in electronic circuits.