1.
What is a major difference between a gas and a liquid?
Correct Answer
A. A liquid is far less compressible than a gas.
Explanation
The major difference between a gas and a liquid is their compressibility. A gas can be easily compressed because its particles are far apart and have more space to move around. On the other hand, a liquid is much denser and its particles are closer together, making it difficult to compress. Therefore, a liquid is far less compressible than a gas.
2.
What is the lifting force of a liquid called?
Correct Answer
C. Buoyance.
Explanation
Buoyancy is the correct answer for the lifting force of a liquid. Buoyancy refers to the upward force exerted on an object immersed in a fluid, such as a liquid. It is caused by the difference in pressure between the top and bottom of the object, with the pressure being greater at the bottom. This pressure difference results in a net upward force, which is known as buoyancy. It is this force that allows objects to float in liquids and is essential in understanding the behavior of submerged and floating objects.
3.
Which best describes immiscible liquids?
Correct Answer
B. One liquid will float on the other.
Explanation
Immiscible liquids are those that do not mix well together. Instead, one liquid will float on top of the other, forming distinct layers. This occurs because the intermolecular forces between the molecules of the two liquids are not strong enough to overcome the forces of attraction within each liquid. As a result, the liquids remain separate and do not form a homogeneous solution.
4.
Which unit of measurement would indicate velocity of flow?
Correct Answer
A. Feet per second
Explanation
The correct answer is "Feet per second." Velocity is a measure of how fast an object is moving in a particular direction. In the context of flow, velocity refers to the speed at which a fluid is moving through a given area. Feet per second is a commonly used unit of measurement for velocity, as it indicates the distance the fluid travels in one second. Gallons per minute, cubic feet per second, and cubic gallons per minute are not units of velocity but rather units of flow rate or volume.
5.
Which physical factor affects the behavior of liquids in both rest and motion?
Correct Answer
D. Gravity, atmospHeric pressure, and applied forces.
Explanation
The behavior of liquids in both rest and motion is affected by gravity, atmospheric pressure, and applied forces. Gravity causes liquids to flow downwards and affects their density. Atmospheric pressure affects the boiling point and evaporation rate of liquids. Applied forces can cause liquids to move or change shape.
6.
What determines the intensity of the excess pressure in a water-hammer wave?
Correct Answer
D. The amount of extinguished velocity.
Explanation
The intensity of the excess pressure in a water-hammer wave is determined by the amount of extinguished velocity. Water hammer occurs when there is a sudden change in the flow rate of a fluid in a pipe, causing a pressure wave to travel through the pipe. The intensity of this pressure wave is directly related to the velocity of the fluid before it is suddenly stopped or slowed down. The greater the extinguished velocity, the higher the intensity of the excess pressure in the water-hammer wave.
7.
Which type of measurement may be used to express pressure?
Correct Answer
D. Pounds per square inch.
Explanation
Pressure is defined as the force exerted on a given area. Pounds per square inch (psi) is a commonly used unit to express pressure, especially in engineering and physics. It represents the amount of force in pounds applied to one square inch of area. Kilograms, pounds, and tons are units of weight, not pressure, and do not take into account the area over which the force is distributed. Therefore, the correct answer is pounds per square inch.
8.
The standard measure for atmospheric pressure is equal to how many pounds per square
inch?
Correct Answer
B. 14.7 psi.
Explanation
The standard measure for atmospheric pressure is 14.7 psi. Atmospheric pressure is the force exerted by the weight of the air above a given point. It is commonly measured in pounds per square inch (psi). This value is considered standard because it represents the average atmospheric pressure at sea level.
9.
What type of pressure reading is also referred to as overpressure?
Correct Answer
B. Gauge pressure.
Explanation
Gauge pressure refers to the pressure reading that is measured relative to atmospheric pressure. It represents the pressure above or below atmospheric pressure. This type of pressure reading is also referred to as overpressure because it indicates the excess pressure above the atmospheric level. Zero pressure, absolute pressure, and atmospheric pressure do not specifically indicate the measurement relative to atmospheric pressure, making gauge pressure the correct answer.
10.
What term is used to describe the total pressure acting as a gas?
Correct Answer
C. Absolute pressure.
Explanation
Absolute pressure is the term used to describe the total pressure acting as a gas. It is the sum of both atmospheric pressure and gauge pressure. Absolute pressure is measured relative to a perfect vacuum, meaning it includes the pressure exerted by the atmosphere. It is an important concept in various fields, such as physics and engineering, as it provides a comprehensive understanding of the total pressure exerted by a gas.
11.
Which temperature scale is commonly used for scientific measurements?
Correct Answer
A. Kelvin scale.
Explanation
The Kelvin scale is commonly used for scientific measurements because it is an absolute temperature scale that starts at absolute zero, the point at which all molecular motion ceases. This makes it ideal for scientific calculations and experiments, as it allows for precise measurements and comparisons. The other options, such as the Rankine, Réaumur, and Fahrenheit scales, are not commonly used in scientific measurements due to their relative nature or limited usage in specific regions.
12.
Which gas law declares that cooling a gas decreases its volume?
Correct Answer
B. Charles’ law.
Explanation
Charles' law states that the volume of a gas is directly proportional to its temperature, assuming that pressure and amount of gas remain constant. According to this law, when a gas is cooled, its temperature decreases, which in turn causes its volume to decrease. This is because the gas molecules have less kinetic energy and move more slowly, resulting in a decrease in the space they occupy. Boyle's law, on the other hand, states that the volume of a gas is inversely proportional to its pressure, Dalton's law deals with the partial pressures of gases in a mixture, and Gay-Lussac's law relates the pressure and temperature of a gas.
13.
Two or more atoms combined is called a
Correct Answer
C. A molecule.
Explanation
When two or more atoms are chemically bonded together, they form a molecule. A molecule is the smallest unit of a compound that retains all the chemical properties of that compound. Compounds are made up of molecules, so while a compound is a combination of atoms, a molecule specifically refers to the bonded atoms. An element, on the other hand, consists of only one type of atom and cannot be broken down into simpler substances. A mixture is a combination of different substances that are not chemically bonded together.
14.
According to the electron theory, atoms are composed of
Correct Answer
A. Protons, neutrons, and electrons.
Explanation
According to the electron theory, atoms are composed of protons, neutrons, and electrons. This theory states that protons and neutrons are located in the nucleus of an atom, while electrons orbit around the nucleus. Protons have a positive charge, neutrons have no charge, and electrons have a negative charge. This combination of particles forms the basic structure of an atom, with protons and neutrons providing the mass and electrons providing the charge. Therefore, the correct answer is protons, neutrons, and electrons.
15.
How do the charges of protons and electrons differ?
Correct Answer
D. Protons have positive charges, and electrons have negative charges.
Explanation
Protons and electrons have opposite charges. Protons have a positive charge, while electrons have a negative charge. This is a fundamental property of these subatomic particles in an atom.
16.
The uniform movement of electrons in a specific direction is called
Correct Answer
C. Electric current.
Explanation
The correct answer is electric current. Electric current refers to the uniform movement of electrons in a specific direction. It is the flow of electric charge through a conductor, such as a wire. This movement of electrons creates a flow of energy, which can be harnessed for various purposes. Electrical potential refers to the potential energy per unit charge at a specific point in an electric field. Free electrons are electrons that are not bound to an atom or molecule. Ionization refers to the process of creating ions by adding or removing electrons from atoms or molecules.
17.
Which shell of the valence electrons determines whether a material is a good or a poor
conductor of electricity?
Correct Answer
A. The outermost shell.
Explanation
The outermost shell of valence electrons determines whether a material is a good or a poor conductor of electricity because it is the shell that is involved in bonding and interacting with other atoms. If the outermost shell is full or nearly full, the material is likely a poor conductor because the electrons are tightly held and not easily free to move and carry an electric current. On the other hand, if the outermost shell is not full, the material is likely a good conductor because the electrons are more loosely held and can easily move and carry an electric current.
18.
Which statement best describes a positive ion?
Correct Answer
B. An atom that lost an electron and has more protons.
Explanation
A positive ion is formed when an atom loses one or more electrons. This results in the atom having more protons than electrons, giving it a positive charge. Therefore, the statement "An atom that lost an electron and has more protons" best describes a positive ion.
19.
What effect of current causes an electric motor to produce mechanical energy?
Correct Answer
B. Magnetism.
Explanation
An electric motor produces mechanical energy due to the effect of magnetism. When an electric current flows through a wire that is placed in a magnetic field, it creates a force that causes the wire to move. This movement is then transferred to the motor's rotor, resulting in mechanical energy. Heat, chemical reactions, and reactance do not directly cause an electric motor to produce mechanical energy.
20.
What is the unit of measurement for electrical power?
Correct Answer
A. Watts.
Explanation
The unit of measurement for electrical power is watts. Watts measure the rate at which electrical energy is consumed or produced. It represents the amount of work done per unit of time, indicating the power of an electrical device or system. Volts measure electrical potential difference, amps measure electrical current, and ohms measure electrical resistance, but none of these units directly measure power.
21.
A 3-horsepower motor consumes how much power?
Correct Answer
D. 2,238 W.
Explanation
A 3-horsepower motor consumes 2,238 watts of power. This can be calculated by converting horsepower to watts using the conversion factor of 746 watts per horsepower. Therefore, 3 horsepower is equal to 3 * 746 = 2,238 watts.
22.
A magnet that is magnetized by induction from an external source is called
Correct Answer
C. An artificial magnet.
Explanation
An artificial magnet is a magnet that is magnetized by induction from an external source, such as electricity. This is different from a natural magnet, which is naturally occurring and does not require any external source for magnetization. An electromagnet, on the other hand, is a type of artificial magnet that is created by passing an electric current through a coil of wire. An electromechanical magnet is not a commonly used term and does not accurately describe a magnet magnetized by induction from an external source.
23.
When do the magnetic lines of force in a magnet cross?
Correct Answer
D. Magnetic lines of force never cross each other.
Explanation
Magnetic lines of force never cross each other because they represent the direction of the magnetic field. If the lines were to cross, it would indicate that the magnetic field has two different directions at the same point, which is not possible. The lines always follow a continuous path from the north pole to the south pole of a magnet, or from a higher magnetic field strength to a lower magnetic field strength.
24.
What are the two most common methods of producing voltage?
Correct Answer
C. Chemical and mechanical.
Explanation
The two most common methods of producing voltage are chemical and mechanical. Chemical methods involve the use of chemical reactions, such as in batteries, to generate an electric potential difference. Mechanical methods involve the use of mechanical energy, such as in generators, to produce a voltage through the principle of electromagnetic induction. Magnetic and heat methods are not the most common methods for producing voltage.
25.
What type of current flow is the result of voltages produced by batteries and
thermocouples?
Correct Answer
B. Direct current.
Explanation
The correct answer is direct current. Direct current is the type of current flow that is produced by batteries and thermocouples. In direct current, the flow of electric charge is unidirectional, meaning it flows in only one direction. This is in contrast to alternating current, where the flow of electric charge periodically changes direction. Therefore, direct current is the appropriate type of current to describe the flow of voltage produced by batteries and thermocouples.
26.
What type(s) of current flow cannot be transformed from a higher voltage to a lower
voltage?
Correct Answer
B. Direct current.
Explanation
Direct current (DC) cannot be transformed from a higher voltage to a lower voltage. This is because DC flows in only one direction and does not change its polarity. Therefore, it cannot be easily converted or transformed to a lower voltage without the use of additional components such as transformers or voltage regulators. In contrast, alternating current (AC) can be easily transformed from a higher voltage to a lower voltage using transformers.
27.
What are the three things needed to produce voltage by the principle of electromagnetic
induction?
Correct Answer
D. Magnetic field, conductor, and relative motion.
Explanation
According to the principle of electromagnetic induction, voltage can be produced by the interaction of a magnetic field, a conductor, and their relative motion. The magnetic field creates a flux, and when the conductor cuts through this flux due to relative motion, an electromotive force is induced, resulting in the production of voltage. Therefore, the correct answer is "Magnetic field, conductor, and relative motion."
28.
What type of material is used to construct the fuel tank on the R–11?
Correct Answer
C. Sheet aluminum alloy.
Explanation
The fuel tank on the R-11 is constructed using a sheet aluminum alloy. This material is commonly used in aerospace applications due to its lightweight yet strong properties. Aluminum alloys offer a good balance between weight reduction and structural integrity, making them an ideal choice for fuel tanks where both durability and weight savings are important factors.
29.
Which is not a type of positive displacement pump?
Correct Answer
D. Centrifugal.
Explanation
The correct answer is Centrifugal because it is not a type of positive displacement pump. Positive displacement pumps operate by trapping a fixed amount of fluid and then forcing it into the discharge pipe, while centrifugal pumps use centrifugal force to move the fluid. Therefore, centrifugal pumps do not fall under the category of positive displacement pumps.
30.
What term is used to define the process that takes place when water forms into droplets after
passing through filter elements?
Correct Answer
C. Coalescing.
Explanation
Coalescing is the term used to define the process that takes place when water forms into droplets after passing through filter elements. Coalescing refers to the merging or coming together of smaller droplets into larger ones. In the context of filtration, coalescing filters are designed to remove small water droplets from a gas or liquid stream by causing them to combine and form larger droplets that can be easily separated. This process is commonly used in various industries, such as oil and gas, to remove water and other contaminants from fluids.
31.
What filter separator component prevents pressure surges from damaging dispensing
pressure control systems?
Correct Answer
A. Air eliminator.
Explanation
An air eliminator is a filter separator component that prevents pressure surges from damaging dispensing pressure control systems. It is designed to remove air or gas bubbles from the fluid being dispensed, ensuring a smooth and consistent flow of the liquid. By eliminating air, the air eliminator helps to maintain a stable pressure and prevents any sudden surges that could potentially damage the dispensing system.
32.
What type of meter is used on most fuel dispensing systems?
Correct Answer
B. Bi-rotor, positive displacement.
Explanation
Bi-rotor, positive displacement meters are commonly used on fuel dispensing systems. These meters are designed to accurately measure the flow of fuel by using two rotors that rotate in opposite directions. The positive displacement technology ensures precise measurement by dividing the flow into fixed, discrete volumes. This type of meter is preferred for fuel dispensing systems due to its accuracy and reliability in measuring fuel quantities.
33.
What item protects fuel dispensing system electrical components against overload?
Correct Answer
A. Automatic reset-type circuit breakers.
Explanation
Automatic reset-type circuit breakers are designed to protect electrical components against overload. These circuit breakers automatically trip and disconnect the circuit when an excessive amount of current flows through it, preventing damage to the electrical components. Once the overload is removed, the circuit breaker automatically resets itself and allows the current to flow again. This feature ensures the continuous and safe operation of the fuel dispensing system by protecting the electrical components from potential damage caused by overload conditions.
34.
What type of lubricant is used to lubricate the power takeoff (PTO) on a fuel dispensing
system?
Correct Answer
B. Ninety-weight gear oil.
Explanation
Ninety-weight gear oil is the correct answer because it is specifically designed for lubricating gears and other heavy-duty components. The power takeoff (PTO) on a fuel dispensing system is a mechanical device that transfers power from the engine to operate the fuel pump. Since the PTO involves gears, it requires a lubricant that can withstand high pressure and provide adequate protection. Ninety-weight gear oil, also known as 90W oil, has the viscosity and additives necessary to ensure smooth operation and prevent wear and tear on the gears.
35.
What component found on R–11s and R–12s prevents the auxiliary throttle from operating
unless the power takeoff (PTO) is engaged?
Correct Answer
B. Throttle interlock system.
Explanation
The throttle interlock system is a component found on R-11s and R-12s that prevents the auxiliary throttle from operating unless the power takeoff (PTO) is engaged. This system ensures that the auxiliary throttle can only be activated when the PTO is in use, providing an added layer of safety and preventing accidental throttle activation.
36.
What fuel dispensing system component controls system fuel pressure?
Correct Answer
A. Bypass system.
Explanation
The bypass system is responsible for controlling the fuel pressure in a fuel dispensing system. It regulates the flow of fuel and ensures that the pressure remains within the desired range. This component is designed to divert excess fuel back to the storage tank, preventing any potential damage or overpressure in the system. By controlling the fuel pressure, the bypass system helps maintain the efficiency and safety of the fuel dispensing system.
37.
During bottom loading operations, what occurs when the signal to the bottom loading optic
probe is lost?
Correct Answer
D. The electronic control module cuts power to the bottom loading electric air solenoid.
Explanation
During bottom loading operations, the signal to the bottom loading optic probe is used to determine the fill level of the tank. If this signal is lost, it indicates a potential issue with the loading process. In order to prevent any further problems, the electronic control module cuts power to the bottom loading electric air solenoid. This action stops the flow of air and prevents any further loading until the issue is resolved.
38.
When should Bourdon gauges be calibrated?
Correct Answer
C. Annually.
Explanation
Bourdon gauges should be calibrated annually. Calibrating them on a yearly basis ensures that they maintain their accuracy and reliability. Regular calibration helps to identify any deviations or inaccuracies in the gauge's measurements, allowing for necessary adjustments or repairs to be made. This ensures that the gauge continues to provide accurate readings and helps prevent any potential errors or safety hazards.
39.
What may a filter separator differential pressure reading below 3 pounds per square inch
(psi) indicate?
Correct Answer
D. A defective O-ring or ruptured coalescers.
Explanation
A filter separator differential pressure reading below 3 psi may indicate a defective O-ring or ruptured coalescers. This is because a low differential pressure suggests that there is not enough resistance in the system, which could be caused by a leak or rupture in the coalescer elements. The O-ring is a common component that can become defective and cause a decrease in pressure.
40.
When performing meter calibrations, what is the acceptable difference between the master
meter and the meter being calibrated?
Correct Answer
A. ½ gallon for each 100 gallons passing through the meter.
Explanation
The acceptable difference between the master meter and the meter being calibrated is ½ gallon for each 100 gallons passing through the meter. This means that for every 100 gallons that pass through the meter being calibrated, there can be a difference of up to ½ gallon between the measurement of the master meter and the meter being calibrated.
41.
Initial tool listings for individual tool kits (ITK) and composite tool kits (CTK) include all
of the following except
Correct Answer
B. Quantity on hand.
Explanation
The initial tool listings for individual tool kits (ITK) and composite tool kits (CTK) include nomenclature, quantity authorized, and tool national stock number (NSN). These listings provide a detailed inventory of the tools included in the kits and their corresponding NSN. However, the quantity on hand is not included in the initial listings as it may vary depending on the usage and availability of the tools.
42.
How often should joint inventories for all individual tool kits (ITK) be accomplished?
Correct Answer
D. Annually.
Explanation
Joint inventories for all individual tool kits should be accomplished annually. This means that once a year, a comprehensive inventory of all the tool kits should be conducted to ensure that all the tools are accounted for and in good condition. This allows for proper maintenance and replacement of any missing or damaged tools, ensuring that the tool kits are complete and ready for use. Conducting joint inventories annually also helps in identifying any discrepancies or issues with the tool kits, allowing for timely resolution and efficient management of the inventory.
43.
What type of time compliance technical order (TCTO) is issued for safety conditions which,
if left uncorrected, could result in fatality or serious injury to personnel or extensive damage to or
destruction of valuable property?
Correct Answer
D. Immediate action.
Explanation
Immediate action TCTOs are issued for safety conditions that, if not corrected, could lead to fatal or serious injuries to personnel or significant damage to valuable property. These TCTOs require immediate attention and prompt corrective action to mitigate potential risks and prevent any harm or damage.
44.
Urgent action time compliance technical orders (TCTO) require compliance within what
maximum amount of days?
Correct Answer
A. 10 days.
Explanation
Urgent action time compliance technical orders (TCTO) are orders that require immediate attention and compliance. These orders are usually issued when there is a critical issue or safety concern that needs to be addressed promptly. The maximum amount of time given to comply with such orders is 10 days. This ensures that the necessary actions are taken quickly to mitigate any potential risks or hazards.
45.
Which publication is a memorandum issued by commercial manufacturers advising
maintainers of minor defects with a product?
Correct Answer
B. Service bulletin.
Explanation
A service bulletin is a publication issued by commercial manufacturers to inform maintainers about minor defects with a product. It provides guidance on how to address these issues and ensure the product's proper functioning. Unlike a TCTO (Time Compliance Technical Order) which deals with mandatory modifications or inspections, a service bulletin focuses on non-mandatory repairs or updates. A technical manual is a comprehensive guide for operating and maintaining a product, while a manufacturer's recall is a formal action taken to address safety or performance issues that may pose a risk to users.
46.
What type of publication is issued when a commercial manufacturer discovers dangerous or
unsafe conditions with a product?
Correct Answer
C. Manufacturer’s recall.
Explanation
A manufacturer's recall is issued when a commercial manufacturer discovers dangerous or unsafe conditions with a product. This publication notifies consumers and retailers that the product has a defect or poses a safety risk, and provides instructions on how to return or repair the product. It is a formal and official action taken by the manufacturer to address the issue and ensure the safety of the consumers.
47.
What type of inspection is performed to determine the condition of a vehicle or piece of
equipment?
Correct Answer
C. Limited technical inspection.
Explanation
A limited technical inspection is performed to determine the condition of a vehicle or piece of equipment. This type of inspection focuses on specific technical aspects of the vehicle or equipment and is usually conducted to identify any potential issues or problems. It may involve checking the functionality of various components, assessing the overall condition, and ensuring compliance with safety standards. Unlike an annual inspection, which is a comprehensive examination, a limited technical inspection is more targeted and specific in nature.
48.
Within what maximum amount of days of receipt will all new and used vehicles and
equipment be inspected by the Air Force activity which receives it?
Correct Answer
C. 60.
Explanation
The correct answer is 60 because it states the maximum amount of days within which all new and used vehicles and equipment will be inspected by the Air Force activity. This means that the inspection process can take anywhere from 1 to 60 days, but it cannot exceed 60 days.
49.
What form is used to record limited technical inspections (LTI) on used vehicles?
Correct Answer
C. AFTO Form 91.
Explanation
The correct answer is AFTO Form 91. This form is used to record limited technical inspections (LTI) on used vehicles. It is specifically designed for this purpose and provides a standardized format for documenting the results of the inspection.
50.
Which of the following may direct shipment of a vehicle with less than 50 percent life
expectancy to satisfy mission requirements?
Correct Answer
C. MAJCOM.
Explanation
MAJCOM stands for Major Command, which is a level of command in the United States Air Force. This level of command has the authority to direct the shipment of a vehicle with less than 50 percent life expectancy to satisfy mission requirements. The LRS commander, wing commander, and HQ USAF may have authority over other aspects of operations, but it is the MAJCOM that has the specific authority mentioned in the question.