2A551 CDCs Volume 2 Of 3 UREs

The given answer is "occupies space". This is because matter is defined as any substance that has mass and occupies space. This means that matter takes up physical space and has a definite volume. The fact that matter can be seen or cannot be compressed are not accurate definitions of matter, as there are substances that are not visible to the naked eye and can be compressed. Therefore, the correct explanation is that matter occupies space.

The correct answer is axle because the axle is the part of the aircraft that supports the weight and allows the wheels to rotate. When changing a tire on an aircraft, a jack is typically used to lift the aircraft off the ground, and this jack is specifically designed to fit and support the axle. The axle jack provides stability and ensures that the aircraft is safely raised for tire maintenance.

Atoms are made up of protons, neutrons, and electrons. Protons and neutrons are located in the nucleus of the atom, while electrons orbit around the nucleus. Protons have a positive charge, neutrons are neutral, and electrons have a negative charge. This combination of particles determines the overall charge and properties of the atom. Molecules are formed when atoms bond together, but they are not the fundamental building blocks of atoms. Therefore, the correct answer is protons, neutrons, electrons.

The term "alternating" refers to something that changes or reverses periodically. In the context of electricity, "alternating current" (AC) is a type of electric current that periodically changes direction. Unlike direct current (DC), which flows in one direction, AC flows back and forth, reversing its direction at regular intervals. Therefore, the correct answer is "alternating" as it accurately describes the characteristic of a current that periodically reverses.

Aircraft have trim systems to correct minor deviations in flight attitude. These systems help maintain the aircraft's stability and balance by adjusting the control surfaces to counteract any unwanted changes in pitch, roll, or yaw. By making small adjustments to the trim settings, pilots can ensure that the aircraft flies smoothly and maintains the desired flight path without the need for constant manual control inputs. This allows the pilot to focus on other aspects of flying and reduces the workload, making the flight safer and more comfortable.

The most outstanding characteristic of a liquid is its ability to conform to the shape of its container. Unlike solids, which have a fixed shape, liquids are able to take on the shape of their container. This is due to the fact that the particles in a liquid are not tightly packed together like in a solid, allowing them to flow and move around. Liquids can fill the space they are in and adjust their shape accordingly. This property is what distinguishes liquids from other states of matter.

When an 8-square-inch piston moves 5 inches within a cylinder, the volume of liquid displaced can be calculated by multiplying the area of the piston (8 square inches) by the distance it moves (5 inches). Therefore, the volume of liquid displaced is 8 square inches x 5 inches = 40 cubic inches.

The greater the current flow through an electromagnet, the greater the strength. This is because the strength of an electromagnet is directly proportional to the amount of current passing through it. As the current increases, the magnetic field produced by the electromagnet becomes stronger, resulting in a greater overall strength.

The correct answer is transformer-rectifier (T-R) because it is the component specifically designed to convert high-voltage AC power into low-voltage DC power. The T-R is responsible for converting the power from the aircraft's electrical system, allowing it to be used by the DC system. This conversion is necessary to ensure that the DC system receives the appropriate voltage and current for proper operation. The other options mentioned, such as the integrated drive generator (IDG), frequency and load generator, and generator control unit (GCU), do not perform the same function of converting AC to DC power.

The most common type of material used for fuselage construction is aluminum alloy. Aluminum alloys are preferred due to their high strength-to-weight ratio, corrosion resistance, and ease of fabrication. They provide excellent structural integrity while keeping the weight of the aircraft relatively low. Steel is heavier and less corrosion resistant, titanium is expensive and difficult to work with, and magnesium is prone to corrosion and has lower strength compared to aluminum alloys. Therefore, aluminum alloy is the most suitable material for fuselage construction.

The flight control surfaces used to make an aircraft climb or dive are elevators. Elevators are located on the horizontal stabilizer at the tail of the aircraft and are responsible for controlling the pitch or the up and down motion of the aircraft. By deflecting the elevators, the pilot can change the angle of the aircraft's nose, causing it to climb or descend. Flaps are used to increase lift during takeoff and landing, spoilers are used to decrease lift and increase drag, and ailerons are used to control the roll or the side-to-side motion of the aircraft.

The resulting force can be calculated by multiplying the pressure exerted on the piston head by the area of the piston head. In this case, the pressure is 50 psi and the area of the piston head is 5 square inches. Multiplying these values gives us 250 pounds, which is the resulting force.

A hydraulic system check valve is designed to allow flow in only one direction. This means that it permits the fluid to flow through the valve in one direction while preventing any backflow or reverse flow. This is important for maintaining the intended flow direction and preventing any unwanted or potentially damaging flow reversal in the hydraulic system.

Aircraft brakes are designed to slow down or stop the motion of the aircraft by utilizing the principle of friction. Friction is created between the brake pads and the rotating wheels, which generates a force that opposes the motion of the aircraft. This frictional force helps to retard or decrease the speed of the aircraft, allowing it to come to a stop or reduce its speed during landing or taxiing. By applying friction, the brakes help to control the motion of the aircraft and ensure safe operations on the runway.

The correct answer is B-4. A scissor-type maintenance stand refers to a type of stand that has a scissor-like mechanism for height adjustment. This type of stand is commonly used in aviation maintenance to provide a stable and adjustable platform for technicians to work on aircraft. The B-4 option is the only one that indicates a scissor-type stand, making it the correct answer.

The correct answer is "longitudinal". The question is asking about the axis that runs from the nose to the tail of the fuselage. The term "longitudinal" refers to lengthwise direction or parallel to the length of an object. Therefore, the axis that extends lengthwise through the fuselage from the nose to the tail is the longitudinal axis.

The correct answer is "gate check valve". A gate check valve is a type of check valve that uses a gate or disc to block the flow of fluid in one direction. When the flow reverses, the gate or disc is pushed open, allowing the fluid to pass through. This type of valve is commonly used in applications where a tight seal is required and where the flow direction needs to be controlled.

For tires with a diameter of 24 inches or more, it is necessary to remove the tire when the wear reaches the bottom of any tread groove for a continuous length of 12 inches. This means that if there is a section of the tread groove that has worn down to a depth of 12 inches or more, the tire should be replaced. This is important for maintaining proper traction and safety on the road.

A cracked radome, which is the protective cover for an antenna, could cause microwave distortion. The crack in the radome can allow external elements such as moisture or debris to enter, interfering with the transmission and reception of microwave signals. This interference can lead to distortions in the microwave signals, affecting the quality and accuracy of the communication.

Plywood was the first practical laminated composite formed because it is made by gluing together multiple layers of thin wood veneers with the grain of each layer running perpendicular to the adjacent layers. This cross-grain construction gives plywood its strength and durability, making it suitable for a wide range of applications in construction and furniture manufacturing. Safety glass and fiberglass are also examples of laminated composites, but plywood predates them in terms of practical use and widespread adoption. Adobe, on the other hand, is not a laminated composite material.

When a solid is subjected to a force that causes it to undergo permanent deformation, it is said to have passed the elastic limit. This means that the solid has been stretched or compressed beyond its ability to return to its original shape and size once the force is removed. The elastic limit is the maximum stress or force that a material can withstand without undergoing permanent deformation. Once the elastic limit is surpassed, the solid will not be able to expand or return to its original state, hence losing its ability to expand.

The antiskid system is designed to prevent wheel skid by releasing pressure from the skidding wheel. When a wheel starts to skid, it loses traction with the road surface, which can lead to loss of control and accidents. By releasing pressure from the skidding wheel, the antiskid system allows the wheel to regain traction and prevent skidding. This helps to maintain stability and control of the vehicle, ensuring safer driving conditions.

An O-ring seal is used to maintain an airtight seal between split wheel halves. O-rings are made of rubber and are designed to fit into a groove between two mating surfaces. When compressed, the O-ring creates a tight seal, preventing any air or fluid from leaking between the wheel halves. This type of seal is commonly used in various applications where a reliable and leak-proof connection is required.

The correct answer is ply rating. The ply rating refers to an aircraft tire's maximum recommended static load. It indicates the number of layers of fabric, or plies, used in the tire's construction, which determines its strength and load-carrying capacity. The higher the ply rating, the greater the tire's ability to support heavier loads. Therefore, the ply rating is an important factor to consider when selecting an aircraft tire that can safely handle the anticipated static load.

Electrons can be released from their outer orbit by various forces such as heat, chemical action, and changing magnetic fields. However, cold temperatures do not have enough energy to overcome the attractive forces that hold electrons in their orbits. Therefore, electrons cannot be released from their outer orbit by cold temperatures.

The correct answer is B-2. This is because the given question states that the maintenance stand has an adjustable height of 13 to 20 feet. Among the options provided, B-2 is the only one that falls within this height range. Therefore, B-2 is the correct answer.

Drag is the force that acts parallel to the relative wind. It is a resistance force that opposes the motion of an object through a fluid, such as air. In the context of aerodynamics, drag is caused by the interaction between the object and the surrounding air molecules. It is influenced by factors such as the shape and size of the object, the speed of the object, and the properties of the fluid. Drag is an important consideration in the design and performance of vehicles and aircraft, as it affects their efficiency and ability to overcome air resistance.

The main difference between inspection plates and panels is their size. Inspection plates are typically smaller in size and are used for accessing small areas or components, while panels are larger and used for accessing larger areas or equipment. Size plays a crucial role in determining the functionality and purpose of these components, as it determines the ease of access and the amount of space available for inspection or maintenance tasks.

A barometer is designed to measure pressure, specifically atmospheric pressure. The unit commonly used to measure atmospheric pressure is inches of mercury (inHg). This unit refers to the height of a column of mercury that the atmospheric pressure can support. As the pressure changes, the height of the mercury column also changes, allowing for the measurement of pressure. Therefore, the correct answer is inches of mercury.

The correct answer is "yaw". Yaw refers to the movement about the vertical axis. It is the rotation of an object or vehicle around its vertical axis, causing it to turn left or right. This movement is commonly observed in aircraft, boats, and other vehicles where changes in direction are made by rotating along the vertical axis.

The correct answer is fowler. The fowler flap is commonly used on bomber and cargo type aircraft. It is a type of flap that extends both rearward and downward when deployed, increasing the wing area and improving lift. This design allows for better low-speed performance and increased lift coefficient, making it suitable for larger aircraft that require shorter takeoff and landing distances.

In hydraulic hand pumps, double-action means that fluid-flow is created with each stroke of the pump handle. This means that every time the pump handle is moved, fluid is forced through the system, creating a continuous flow. This is different from the other options, where fluid-flow is created either with every other stroke or where double volume is displaced with each stroke.

The correct answer is the nutating plate. In the Stratopower variable-volume pump, the nutating plate is responsible for holding the pistons in contact with the cam plate. This plate moves in a circular motion, creating a reciprocating motion in the pistons, which allows for the pumping action of the pump. The nutating plate ensures that the pistons maintain contact with the cam plate, allowing for efficient and effective pumping.

A restrictor check valve allows the normal operating speed of a hydraulic actuator in one direction while limiting the speed in the other direction. This valve has a built-in restriction that slows down the flow of hydraulic fluid in one direction, providing controlled movement. In the other direction, the check valve allows unrestricted flow, allowing the actuator to move at its normal speed. This valve is commonly used in hydraulic systems to control the speed and direction of actuator movement.

The purpose of the torsion links on a main landing gear is to prevent the inner cylinder from rotating within the outer cylinder. Torsion links are designed to provide stability and control by limiting the rotational movement between the inner and outer cylinders of the landing gear. This prevents any unwanted rotation that could affect the aircraft's performance during landing or takeoff. By restricting the rotation, the torsion links ensure that the landing gear functions properly and maintains its intended position.

The split wheel is balanced individually by halves during buildup. This means that each half of the wheel is balanced separately to ensure that the weight distribution is even. This is important because an unbalanced wheel can cause vibrations and uneven wear on tires, leading to potential safety hazards. By balancing each half of the wheel individually, it ensures that the entire assembly will be properly balanced and function smoothly.

The term "phase" is used to express a condition in which two moving objects are changing in or out of step. In the context of electrical systems, phase refers to the relationship between two alternating currents or voltages. When two currents or voltages are in phase, they reach their peaks and zero points at the same time. When they are out of phase, their peaks and zero points do not align. This concept is important in understanding the behavior and synchronization of electrical systems.

The correct answer is 40,000 lbs because it falls within a reasonable weight range for a class I MB-2 tractor. The other options are either too light or too heavy to be considered plausible weights for this type of tractor.

The correct answer is "manual." A manual flight control system allows the pilot to directly control the aircraft even if hydraulic pressure is lost. This means that the pilot can still maneuver the aircraft using physical force without relying on hydraulic assistance. This type of system provides a backup option in case of hydraulic failure, ensuring that the pilot can maintain control over the aircraft.

A micron is a unit of measurement equal to one millionth of a meter. Since there are 39.37 inches in a meter, one millionth of a meter is equal to one millionth of 39.37 inches, which is approximately 0.00003937 inches. Therefore, one micron is equivalent to millionths of an inch.

The term "cracking pressure" refers to the pressure at which the relief valve ball is slightly unseated. This means that the valve opens just enough to allow fluid or gas to escape, relieving pressure from the system. It is called "cracking pressure" because it is the minimum pressure required to crack open the valve and start the relief process.

The correct answer is metering pin. The shock strut component that controls the rate of fluid-flow through the orifice is the metering pin. The metering pin regulates the flow of fluid in the shock strut, allowing for controlled damping and absorption of shocks and vibrations. It restricts the flow of fluid, controlling the rate at which it passes through the orifice, thereby affecting the overall performance and stability of the shock strut system.

The correct answer is tapered roller. Tapered roller bearings are commonly used on aircraft wheels because they can handle both radial and axial loads. These bearings have a cone-shaped inner and outer ring, which allows for efficient distribution of forces and reduces friction. The tapered design also helps with proper alignment and stability, making them suitable for the high-speed and heavy-duty requirements of aircraft wheels.

Liquid oxygen (LOX) has a boiling point of -297 degrees Fahrenheit. Boiling point refers to the temperature at which a substance changes from its liquid state to its gaseous state. In the case of LOX, it boils and becomes a gas at -297 degrees Fahrenheit. This extremely low boiling point is due to the fact that oxygen molecules have weak intermolecular forces, which makes it easier for them to escape the liquid phase and become a gas.

The model 4000 engine trailer is capable of supporting a maximum load of 8,000 pounds. This means that the trailer is designed and built to handle weights up to 8,000 pounds without any issues or risks of damage. It is important to adhere to this weight limit to ensure the safety and proper functioning of the trailer during transportation.

The correct answer is 27 gallons. This is determined by the given information that the amount of fluid the MJ-2A reservoir holds is 27 gallons.

Stringers are structural members in an aircraft that give shape to the aircraft and provide a means for attaching the skin to the structure. They are long, thin, and run longitudinally along the fuselage, wings, or other parts of the aircraft. Stringers help to distribute loads and provide rigidity to the structure, ensuring the overall strength and stability of the aircraft.

Waterlines are the reference locations that are measured vertically from a reference datum, which is typically below the aircraft. These reference lines are used to determine the water level and to assess the buoyancy and stability of the aircraft. They help in designing and constructing the aircraft's hull or body, ensuring that it is properly balanced and can float or move through water efficiently. Therefore, waterlines are the correct answer in this context.

The atmospheric pressure at sea level is 14.7 psi. This is the standard value for atmospheric pressure at sea level and is commonly used as a reference point for pressure measurements. Atmospheric pressure is the force exerted by the weight of the air above a certain point and it decreases as altitude increases. At sea level, the weight of the air column above is the highest, resulting in a pressure of 14.7 psi.

Variable-volume pumps do not require a separate pressure-regulating device in the system because they have an integral compensator. An integral compensator is a built-in mechanism in the pump that automatically adjusts the flow rate according to the pressure requirements of the system. This means that the pump can regulate its own pressure without the need for an additional device.