# CDC Volume 2 UREs 2AX5X

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Questions and Answers
• 1.

### Atmospheric pressure at sea level is?

• A.

14.7 PSI

• B.

17.4 PSI

• C.

29.92 PSI

• D.

29.29 PSI

Correct Answer
A. 14.7 PSI
Explanation
Atmospheric pressure at sea level is commonly measured as 14.7 PSI. This value represents the average pressure exerted by the Earth's atmosphere at sea level. It is important to note that atmospheric pressure can vary slightly due to factors such as weather conditions and altitude, but 14.7 PSI is generally accepted as the standard measurement at sea level.

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• 2.

### A barometer is designed to measure pressure in?

• A.

Pounds per square inch

• B.

Inches of mercury

• C.

Milibars of alcohol

• D.

Ounces of air

Correct Answer
B. Inches of mercury
Explanation
A barometer is designed to measure pressure in inches of mercury. This is because the most common type of barometer, called a mercury barometer, uses a column of mercury to measure atmospheric pressure. The height of the mercury column in the barometer is directly related to the atmospheric pressure, with higher pressure causing the mercury to rise and lower pressure causing it to fall. Therefore, the measurement is given in inches of mercury, indicating the height of the mercury column.

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• 3.

### The primary force an airfoil has to defeat is

• A.

Lift

• B.

Drag

• C.

Thrust

• D.

Weight

Correct Answer
D. Weight
Explanation
The primary force an airfoil has to defeat is weight. Weight is the force exerted on an object due to gravity. In order for an airfoil to generate lift and stay in the air, it needs to overcome the force of gravity pulling it down. Drag is the resistance encountered by the airfoil as it moves through the air, thrust is the force propelling the airfoil forward, and lift is the upward force generated by the airfoil's shape. However, the airfoil must first overcome its weight before any of these other forces can come into play.

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• 4.

### The force that acts upward at a right angle to the direction of the relative wind is

• A.

Lift

• B.

Drag

• C.

Thrust

• D.

Weight

Correct Answer
A. Lift
Explanation
Lift is the force that acts upward at a right angle to the direction of the relative wind. It is the force that allows an object, such as an airplane, to stay in the air and counteracts the force of gravity. Lift is generated by the interaction between the shape of the object, such as the wings of an airplane, and the flow of air around it.

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• 5.

### The force that acts parallel to the relative wind is

• A.

Lift

• B.

Drag

• C.

Thrust

• D.

Weight

Correct Answer
B. Drag
Explanation
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 air molecules. It is important to minimize drag in order to maximize the efficiency and speed of an object moving through a fluid medium.

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• 6.

### The stress that resists the force tending to cause one layer of material to slide over an adjacent layer is called

• A.

Bending

• B.

Tension

• C.

Torsion

• D.

Shear

Correct Answer
D. Shear
Explanation
Shear stress refers to the stress that opposes the force that tries to cause one layer of material to slide over an adjacent layer. It occurs when two layers of material slide past each other in opposite directions. This type of stress is commonly observed in materials such as metals and can lead to deformation or failure if it exceeds the material's shear strength.

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• 7.

### What is the design that uses any combination of longerons, stringers, bulkheads, and frames in the construction of the fuselage called?

• A.

Fuselage

• B.

Longerons

• C.

Monocoque

• D.

Semi-monocoque

Correct Answer
D. Semi-monocoque
Explanation
A semi-monocoque design is a type of fuselage construction that utilizes a combination of longerons, stringers, bulkheads, and frames. In this design, the skin of the fuselage is not solely responsible for carrying the structural loads but is supported by internal structural components such as longerons, stringers, bulkheads, and frames. This design provides a good balance between strength, weight, and flexibility, making it a commonly used construction method for modern aircraft fuselages.

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• 8.

### The structural members used to give shape to the aircraft and provide a means for attaching the skin to the structure are called

• A.

Longerons

• B.

Bulkheads

• C.

Stringers

• D.

Frames

Correct Answer
C. Stringers
Explanation
Stringers are structural members that are used to give shape to the aircraft and provide a means for attaching the skin to the structure. They run longitudinally along the fuselage and wings, helping to distribute loads and maintain the structural integrity of the aircraft. Longerons are longer structural members that run parallel to the fuselage, providing additional strength and support. Bulkheads are vertical partitions that separate different compartments within the aircraft. Frames are horizontal structural members that provide support and shape to the aircraft structure. Therefore, out of the given options, stringers are the correct answer.

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• 9.

### The most common type of material used for fuselage construction is

• A.

Steel

• B.

Titanium

• C.

Magnesium

• D.

Aluminum alloy

Correct Answer
D. Aluminum alloy
Explanation
Aluminum alloy is the most common type of material used for fuselage construction due to its favorable properties. It is lightweight, which helps reduce the overall weight of the aircraft, leading to improved fuel efficiency. Aluminum alloy also possesses high strength-to-weight ratio, making it durable and capable of withstanding the stresses and loads experienced during flight. Additionally, it is corrosion-resistant, ensuring the longevity of the fuselage. These factors make aluminum alloy a preferred choice for fuselage construction in the aviation industry.

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• 10.

### The wing design used on most modern military aircraft is

• A.

Cantilever

• B.

Monocoque

• C.

External braced

• D.

Semi-monocoque

Correct Answer
A. Cantilever
Explanation
The correct answer is cantilever. Cantilever wing design refers to a wing that is self-supporting and does not require external bracing or support structures. This design is commonly used in modern military aircraft as it offers better aerodynamic efficiency and reduces drag. The cantilever design allows for a sleeker and more streamlined aircraft, enhancing its maneuverability and overall performance.

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• 11.

### The fixed vertical surface of the empennage is called the

• A.

Stabilator

• B.

Elevator

• C.

Rudder

• D.

Fin

Correct Answer
D. Fin
Explanation
The correct answer is "fin". The fin is the fixed vertical surface of the empennage, which is the tail section of an aircraft. It provides stability and helps to keep the aircraft's nose pointed straight during flight. The stabilator is a combination of a stabilizer and an elevator, which is a movable horizontal surface used for pitch control. The elevator is also a movable surface, but it is located on the horizontal stabilizer and is used for controlling the aircraft's pitch. The rudder is a movable surface located on the vertical stabilizer, and it is used for controlling the aircraft's yaw.

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• 12.

### Engine mounts are typically made of corrosion-resistant steel that is able to withstand forces of

• A.

120,000 to 140,000 PSI

• B.

150,000 to 170,000 PSI

• C.

180,000 to 200,000 PSI

• D.

210,000 to 230,000 PSI

Correct Answer
C. 180,000 to 200,000 PSI
Explanation
Engine mounts are designed to withstand the forces and vibrations generated by the engine. These forces can be quite high, and therefore, the engine mounts need to be made of a material that is strong and durable. Corrosion-resistant steel is commonly used for this purpose. The given answer range of 180,000 to 200,000 PSI indicates the tensile strength of the steel used in engine mounts. This means that the steel can withstand forces in the range of 180,000 to 200,000 pounds per square inch without breaking or deforming, making it suitable for the demanding conditions of engine mounting.

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• 13.

### The main difference between inspection plates and panels is

• A.

Size

• B.

Material

• C.

Location

• D.

Installation

Correct Answer
A. Size
Explanation
Inspection plates and panels differ primarily in terms of their size. While the size of inspection plates may vary, they are typically smaller in comparison to panels. Inspection plates are generally designed to provide access to specific areas for inspection or maintenance purposes. On the other hand, panels are larger structures that serve as covers or enclosures for various components or systems. The difference in size between inspection plates and panels allows for their specific functions and applications in different contexts.

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• 14.

### A network of ultrafine cracks that form on or under the surface of transparent plastics is called

• A.

Crazing

• B.

Casting

• C.

Fretting

• D.

Pitting

Correct Answer
A. Crazing
Explanation
Crazing refers to the network of ultrafine cracks that develop on or under the surface of transparent plastics. This phenomenon occurs due to stress or environmental factors, causing the material to weaken and form these cracks. Crazing is commonly seen in acrylics and other transparent plastics, and it can affect the appearance and structural integrity of the material.

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• 15.

### What are the reference locations in the vertical direction measured from a reference datum that is usually well below the aircraft called?

• A.

Buttlines

• B.

Waterlines

• C.

Buttock stations

• D.

Fuselage stations

Correct Answer
B. Waterlines
Explanation
The reference locations in the vertical direction measured from a reference datum that is usually well below the aircraft are called waterlines. Waterlines are horizontal reference lines that are used to measure the vertical position of various components of an aircraft, such as the wings, fuselage, and other structural elements. These waterlines are typically referenced to a point below the aircraft, such as the waterline on a ship or the ground level for land-based vehicles.

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• 16.

### Movement about the vertical axis is called

• A.

Roll

• B.

Yaw

• C.

Crab

• D.

Pitch

Correct Answer
B. Yaw
Explanation
Yaw refers to the rotational movement about the vertical axis. It is the movement that causes an object to turn left or right. Roll refers to the rotational movement about the longitudinal axis, pitch refers to the rotational movement about the lateral axis, and crab refers to the sideways movement of an aircraft caused by the wind. Therefore, the correct answer is yaw.

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• 17.

### Which flight control surface controls the aircraft about the longitudinal axis?

• A.

Rudder

• B.

Aileron

• C.

Elevator

• D.

Wing flaps

Correct Answer
B. Aileron
Explanation
The aileron is the flight control surface that controls the aircraft about the longitudinal axis. It is located on the outer trailing edge of each wing and is used to create a differential lift, causing the aircraft to roll and bank. By deflecting the ailerons, the pilot can control the aircraft's roll and maintain balance during turns. The rudder controls the aircraft about the vertical axis, the elevator controls the aircraft about the lateral axis, and the wing flaps are used to increase lift and decrease stall speed during takeoff and landing.

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• 18.

### Which of these is attached to the trailing edge of a horizontal stabilizer?

• A.

Flap

• B.

Spoiler

• C.

Rudder

• D.

Elevator

Correct Answer
D. Elevator
Explanation
The elevator is attached to the trailing edge of a horizontal stabilizer. It is a movable control surface that is used to control the pitch of an aircraft. By changing the position of the elevator, the pilot can adjust the aircraft's nose-up or nose-down attitude, allowing for changes in altitude and maintaining stability during flight.

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• 19.

### When making a right turn, the relative position of the ailerons id the right aileron trailing edge is

• A.

Up, left aileron trailing edge is up

• B.

Up, left aileron trailing edge is down

• C.

Down, left aileron trailing edge is up

• D.

Down, left aileron trailing edge is down

Correct Answer
B. Up, left aileron trailing edge is down
Explanation
When making a right turn, the relative position of the ailerons is such that the right aileron trailing edge is up and the left aileron trailing edge is down. This configuration helps to increase the lift on the right wing and decrease the lift on the left wing, causing the aircraft to roll to the right. By raising the trailing edge of the right aileron and lowering the trailing edge of the left aileron, the pilot can effectively control the aircraft's roll and execute a right turn.

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• 20.

### The purpose of wing flaps is to

• A.

Increase lift and drag

• B.

Decrease lift and drag

• C.

Increase lift and decrease drag

• D.

Decrease lift and increase drag

Correct Answer
A. Increase lift and drag
Explanation
Wing flaps are used to increase lift and drag. By extending the flaps, the curvature of the wing increases, which generates more lift. This is particularly useful during takeoff and landing when the aircraft needs more lift at lower speeds. However, the increased curvature also creates more drag, which helps to slow down the aircraft during landing. Therefore, the purpose of wing flaps is to simultaneously increase lift and drag.

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• 21.

### The purpose of aircraft trim system is to

• A.

Reduce the amount of lift

• B.

Prevent the aircraft from stalling

• C.

Correct minor deviations in flight attitude

• D.

Improve augmented lateral control surface movement

Correct Answer
C. Correct minor deviations in flight attitude
Explanation
The purpose of the aircraft trim system is to correct minor deviations in flight attitude. This system helps in maintaining the desired pitch, roll, and yaw of the aircraft during flight. It allows pilots to adjust the control surfaces to counterbalance any imbalances caused by factors like weight distribution, fuel consumption, or changes in the center of gravity. By making these minor adjustments, the trim system ensures that the aircraft flies smoothly and efficiently, reducing the workload on the pilot and improving overall flight stability.

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• 22.

### Matter is any substance that has mass and

• A.

Can be seen

• B.

Occupies space

• C.

Has constant volume

• D.

Cannot be compressed

Correct Answer
B. Occupies space
Explanation
The correct answer is "occupies space" because matter is defined as any substance that has mass and takes up space. This means that matter has volume and can be measured in terms of the space it occupies. Therefore, the statement "occupies space" accurately describes one of the essential characteristics of matter.

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• 23.

### Atoms are made of

• A.

Molecules, protons, neutrons

• B.

Protons, molecules, electrons

• C.

Molecules, neutrons, electrons

• D.

Protons, neutrons, electrons

Correct Answer
D. Protons, neutrons, electrons
Explanation
Atoms are made up of protons, neutrons, and electrons. Protons are positively charged particles found in the nucleus of an atom, while neutrons are neutrally charged particles also found in the nucleus. Electrons, on the other hand, are negatively charged particles that orbit around the nucleus. These three subatomic particles together make up the structure of an atom. Molecules, which are composed of two or more atoms, are not the fundamental building blocks of atoms. Therefore, the correct answer is protons, neutrons, electrons.

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• 24.

### Electrons can be released from their order orbit by all of the following forces except

• A.

Heat

• B.

Cold

• C.

Chemical action

• D.

Changing magnetic field

Correct Answer
B. Cold
Explanation
Electrons can be released from their orbit by heat, chemical action, and changing magnetic fields. However, cold temperatures do not possess enough energy to disrupt the stability of electrons in their orbits and release them. Therefore, cold is the only force listed that cannot release electrons from their order orbit.

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• 25.

### What is the electrical pressure that causes electrons to flow through the conductor called?

• A.

Chemical swap

• B.

Crossfeed field

• C.

Electromotive force

• D.

Transferring magnetic field

Correct Answer
C. Electromotive force
Explanation
Electromotive force is the correct answer because it refers to the electrical pressure or potential difference that causes the flow of electrons through a conductor. It is responsible for driving the current in a circuit and is typically measured in volts. The other options, chemical swap, crossfeed field, and transferring magnetic field, do not accurately describe the electrical pressure that causes electron flow.

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• 26.

### If you applied 24 volts through a total resistance of 6 ohms in a series circuit, the amperage would be?

• A.

2

• B.

4

• C.

6

• D.

18

Correct Answer
B. 4
Explanation
In a series circuit, the total resistance is the sum of all resistances. Here, the total resistance is given as 6 ohms. According to Ohm's Law, the current (amperage) in a circuit is equal to the voltage divided by the resistance. Therefore, the amperage can be calculated by dividing the given voltage of 24 volts by the total resistance of 6 ohms. The result is 4 amperes, which is the correct answer.

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• 27.

### A permanent magnet is produced from a material with

• A.

Low reluctance, and low permeability

• B.

High reluctance, and low permeability

• C.

High reluctance, and high permeability

• D.

High permeability, and low retentivity

Correct Answer
B. High reluctance, and low permeability
Explanation
A permanent magnet is produced from a material with high reluctance, and low permeability. Reluctance refers to the opposition of a material to the flow of magnetic flux, and in the case of a permanent magnet, high reluctance ensures that the magnetic field remains concentrated within the magnet. Low permeability means that the material does not readily allow the magnetic field to pass through it, which helps in maintaining the magnet's strength. Therefore, a material with high reluctance and low permeability is ideal for producing a permanent magnet.

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• 28.

### When soft iron is brought to a permanent magnet it is

• A.

Charged

• B.

Repelled

• C.

Energized

• D.

Magnetized

Correct Answer
D. Magnetized
Explanation
When soft iron is brought near a permanent magnet, it becomes magnetized. This is because soft iron is a ferromagnetic material, meaning it can be easily magnetized. When it comes in contact with a permanent magnet, the domains within the soft iron align themselves with the magnetic field of the magnet, creating a magnetic field within the soft iron itself. This magnetization is temporary and will disappear once the soft iron is no longer in contact with the permanent magnet.

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• 29.

### The greater the current flow through an electromagnet, the

• A.

Less the strength

• B.

Greater the strength

• C.

Greater the retentively

• D.

Higher the reluctance of the core

Correct Answer
B. Greater the strength
Explanation
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 flowing through it. As the current increases, the magnetic field produced by the electromagnet becomes stronger, resulting in a greater overall strength.

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• 30.

### Current flow in most aircraft circuits is controlled by

• A.

Fuses

• B.

Signals

• C.

Batteries

• D.

Switches

Correct Answer
D. Switches
Explanation
In aircraft circuits, the current flow is controlled by switches. Switches are used to open or close the circuit, allowing or preventing the flow of electricity. They provide a means to control the electrical system, turning it on or off as needed. Fuses are used to protect the circuit from excessive current, but they do not directly control the flow of current. Signals are used for communication and do not control current flow. Batteries provide the power source for the electrical system but do not control the flow of current.

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• 31.

### The majority of aircraft circuit protection devise are normally located

• A.

In the aircraft cabin

• B.

In the nose wheel well

• C.

In the utility compartments

• D.

As far as possible from the unit being protected

Correct Answer
A. In the aircraft cabin
Explanation
The majority of aircraft circuit protection devices are normally located in the aircraft cabin because it allows for easy accessibility and maintenance. Placing them in the cabin ensures that they can be easily monitored and repaired if necessary. Additionally, locating them in the cabin reduces the risk of damage or malfunction due to external factors such as weather conditions or physical impact.

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• 32.

### What term describes current that reverses its direction at regularly recurring intervals?

• A.

Direct

• B.

Inductive

• C.

Reversing

• D.

Alternating

Correct Answer
D. Alternating
Explanation
Alternating current (AC) is a term used to describe current that reverses its direction at regularly recurring intervals. Unlike direct current (DC), which flows in one direction, AC changes direction periodically, typically in a sinusoidal waveform. This type of current is commonly used in household electrical systems and is more efficient for long-distance power transmission.

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• 33.

### The methods used to cool brushless alternating current (AC) generators are

• A.

Blast air and ram air

• B.

Engine oil and blast air

• C.

Blast air and generator oil

• D.

Generator oil and engine oil

Correct Answer
B. Engine oil and blast air
Explanation
The correct answer is engine oil and blast air. Brushless AC generators are cooled using a combination of engine oil and blast air. Engine oil is used to cool the internal components of the generator, such as the stator and rotor, which can generate heat during operation. Blast air is then used to further cool the generator by blowing air over the external surfaces, dissipating heat and preventing overheating. This combination of engine oil and blast air ensures efficient cooling and optimal performance of the generator.

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• 34.

### The output of the constant speed drive used to drive a 60/80 kilovolt ampere generator is approximately

• A.

4,000 RPM

• B.

6,000 RPM

• C.

8,000 RPM

• D.

10,000 RPM

Correct Answer
C. 8,000 RPM
Explanation
The correct answer is 8,000 RPM. A constant speed drive is used to maintain a consistent rotational speed in a generator. In this case, the drive is used for a 60/80 kilovolt ampere generator. The speed at which the drive operates is approximately 8,000 RPM, ensuring that the generator produces a steady output of power.

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• 35.

### The underspeed switch on the 60/80 kilovolt ampere generator constant speed drive actuates at

• A.

325 Hz

• B.

345 Hz

• C.

365 Hz

• D.

395 Hz

Correct Answer
C. 365 Hz
Explanation
The underspeed switch on the 60/80 kilovolt ampere generator constant speed drive actuates at 365 Hz. This means that when the generator's frequency drops below 365 Hz, the underspeed switch will be activated. This switch is a safety feature that helps protect the generator from operating at dangerously low speeds, which could potentially damage the equipment or cause a power outage.

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• 36.

### What supplies rotary power to the input gear of the constant speed drive?

• A.

Accessory gearbox

• B.

Transmission shaft

• C.

Torque converter

• D.

Hydraulic gear

Correct Answer
A. Accessory gearbox
Explanation
The accessory gearbox supplies rotary power to the input gear of the constant speed drive. It is responsible for transferring power from the engine to various accessories and components of the system. This gearbox allows for the efficient and controlled transmission of power, ensuring that the constant speed drive receives the necessary rotational force to operate effectively.

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• 37.

### The nickel-cadmium battery can be fully charged only by

• A.

Pulsating current

• B.

Constant current

• C.

Varying current

• D.

Eddy current

Correct Answer
B. Constant current
Explanation
A nickel-cadmium battery can be fully charged only by a constant current. This is because the charging process for this type of battery requires a steady flow of current to ensure that the nickel and cadmium materials within the battery are properly charged. Pulsating current, varying current, and eddy current are not suitable for fully charging the battery as they do not provide a consistent and stable flow of current. Only a constant current can ensure that the battery reaches its maximum charge capacity.

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• 38.

### A battery's internal component that is a grid or framework which supports the active chemical materials is called the

• A.

Plate

• B.

Separator

• C.

Electrolyte

• D.

Chemical solution

Correct Answer
A. Plate
Explanation
The correct answer is plate. In a battery, the plate is the internal component that acts as a grid or framework to support the active chemical materials. The plate helps to hold the active chemicals in place and allows for the flow of electrons during the battery's operation. Without the plate, the battery would not be able to function properly.

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• 39.

### A 24-volt nickel-cadmium battery has

• A.

12 cells

• B.

19 cells

• C.

20 cells

• D.

24 cells

Correct Answer
B. 19 cells
Explanation
A 24-volt nickel-cadmium battery typically consists of multiple cells connected in series. Each cell has a nominal voltage of 1.2 volts. To achieve a total voltage of 24 volts, the battery would require 20 cells (20 cells x 1.2 volts = 24 volts). Therefore, the correct answer is 20 cells.

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• 40.

### What type of motor can operate on alternating current or direct current?

• A.

Shunt

• B.

Circuit

• C.

Universal

• D.

Compound

Correct Answer
C. Universal
Explanation
A universal motor can operate on both alternating current (AC) and direct current (DC). This type of motor is designed with a series field winding and a parallel field winding, allowing it to work with both types of current. The series field winding provides high starting torque, making it suitable for applications that require a lot of power at startup. The parallel field winding helps regulate the speed and provides good speed control. Universal motors are commonly used in household appliances like blenders and vacuum cleaners, where they need to be able to operate on both AC and DC power sources.

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• 41.

### A shunt type motor has

• A.

Less speed regulation than a universal motor

• B.

A field winding series with the armature

• C.

Low starting torque and good speed regulation

• D.

High starting torque and poor speed regulation

Correct Answer
C. Low starting torque and good speed regulation
Explanation
A shunt type motor has low starting torque and good speed regulation because it has a field winding that is connected in parallel (shunt) with the armature. This configuration allows the motor to have a relatively constant speed regardless of the load, resulting in good speed regulation. However, the shunt motor has a lower starting torque compared to other types of motors, which means it may struggle to start heavy loads.

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• 42.

### The three states of matter are

• A.

Liquids, solids, and gases

• B.

Liquids, gases, and minerals

• C.

Gases, solids, and minerals

• D.

Gases, solids, and organic

Correct Answer
A. Liquids, solids, and gases
Explanation
The three states of matter are liquids, solids, and gases. Liquids have a definite volume but not a definite shape, as they take the shape of their container. Solids have a definite shape and volume, as their particles are tightly packed together. Gases have neither a definite shape nor volume, as their particles are spread out and move freely. Minerals and organic are not states of matter, but rather classifications of substances.

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• 43.

### When any force causes a solid to change permanently, the solid is said to have

• A.

Passed its elastic limit

• B.

Lost the ability to expand

• C.

Failed to meet the elastic limit

• D.

Passed the compression limit

Correct Answer
A. Passed its elastic limit
Explanation
When any force causes a solid to change permanently, it means that the solid has passed its elastic limit. The elastic limit is the maximum stress or force that a solid material can withstand without undergoing permanent deformation. Once the elastic limit is exceeded, the solid will not be able to return to its original shape and size when the force is removed. Therefore, the correct answer is "passed its elastic limit".

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• 44.

### The most outstanding characteristic of a liquid is its

• A.

Rigidity

• B.

Usability

• C.

Ability to compress within its container

• D.

Ability to conform to the shape of its container

Correct Answer
D. Ability to conform to the shape of its container
Explanation
The correct answer is "ability to conform to the shape of its container." Liquids have the unique property of being able to take the shape of their container, unlike solids which have a fixed shape. This is because the particles in a liquid are free to move and flow, allowing them to fill the container evenly. Liquids are not rigid like solids, and they cannot be compressed like gases. Therefore, the most outstanding characteristic of a liquid is its ability to conform to the shape of its container.

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• 45.

### What usually produces flow in a pneudraulic system?

• A.

Relief valve in lines

• B.

Piston pushing the fluid

• C.

Scupper pushing the fluid

• D.

Selector valve in the lines

Correct Answer
B. Piston pushing the fluid
Explanation
In a pneudraulic system, flow is typically produced by the piston pushing the fluid. The piston creates pressure within the system, which then causes the fluid to flow through the lines. The other options mentioned, such as the relief valve, scupper, and selector valve, may have roles in regulating or controlling the flow of the fluid, but they do not directly produce the flow.

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• 46.

### Who was among the first to study the compressibility of gases?

• A.

Hook

• B.

Boyle

• C.

Pascal

• D.

Charles

Correct Answer
B. Boyle
Explanation
Boyle was among the first to study the compressibility of gases. He formulated Boyle's law, which states that the pressure and volume of a gas are inversely proportional at a constant temperature. This groundbreaking work laid the foundation for the understanding of gas behavior and the development of the field of thermodynamics. Boyle's contributions to the study of gases were instrumental in advancing scientific knowledge in this area.

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• 47.

### If 50 pounds per square inch of a cylinder pressure acts on a 5-square inch piston head, what will the resulting force be?

• A.

150 pounds

• B.

200 pounds

• C.

250 pounds

• D.

300 pounds

Correct Answer
C. 250 pounds
Explanation
The resulting force can be calculated by multiplying the pressure (50 pounds per square inch) by the area of the piston head (5 square inches). This gives us a force of 250 pounds.

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• 48.

### When an 8-square inch piston moves 5 inches within a cylinder, what volume of liquid is displaced?

• A.

4 cubic inches

• B.

40 cubic inches

• C.

400 cubic inches

• D.

4,000 cubic inches

Correct Answer
B. 40 cubic inches
Explanation
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). This gives us a volume of 40 cubic inches.

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• 49.

### Turbulence affects fluid-flow in a hydraulic line by

• A.

Increasing velocity and viscosity

• B.

Increasing volume and displacement

• C.

Creating resistance and loss of energy

• D.

Creating resistance and energy increases

Correct Answer
C. Creating resistance and loss of energy
Explanation
Turbulence in a hydraulic line disrupts the smooth flow of fluid, causing resistance to the flow. This resistance leads to a loss of energy as the fluid encounters obstacles and experiences friction. Therefore, turbulence affects fluid-flow in a hydraulic line by creating resistance and resulting in a loss of energy.

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• 50.

### A tube whose cross-section area is gradually reduced to a smaller size diameter is called

• A.

Torus

• B.

Pipette

• C.

Vortex

• D.

Venturi

Correct Answer
D. Venturi
Explanation
A tube whose cross-section area is gradually reduced to a smaller size diameter is called a venturi. This type of tube is commonly used in fluid mechanics to measure the flow rate of fluids. The gradual reduction in diameter creates a pressure difference between the wider and narrower sections of the tube, causing the fluid to flow faster in the narrower section. This principle is utilized in various applications, such as carburetors and vacuum cleaners, where the venturi effect is used to create suction or mix air and fuel efficiently.

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Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

• Current Version
• Mar 21, 2023
Quiz Edited by
ProProfs Editorial Team
• Jun 07, 2015
Quiz Created by
Teenaduhon

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