1.
A stable air mass is most likely to have which characteristic?
Correct Answer
B. Poor surface visibility.
Explanation
A stable air mass is most likely to have poor surface visibility because stable air prevents vertical mixing and keeps pollutants trapped near the surface. This can result in hazy or foggy conditions, reducing visibility. Showery precipitation and turbulent air are more commonly associated with unstable air masses where vertical mixing is more prevalent.
2.
The suffix "nimbus,'' used in naming clouds, means:
Correct Answer
A. A rain cloud.
Explanation
The suffix "nimbus" is used in cloud names to indicate that the cloud is associated with precipitation, specifically rain. This suffix is commonly used for clouds that are producing or are about to produce rain. Therefore, the correct answer is "a rain cloud."
3.
Clouds are divided into four families according to their:
Correct Answer
A. Height range.
Explanation
Clouds are classified into different families based on their height range. This classification helps in understanding and predicting weather patterns. The height range of clouds is an important factor as it determines the type of cloud formation and the atmospheric conditions at that altitude. By categorizing clouds based on their height range, meteorologists can analyze and interpret the cloud formations to make accurate weather forecasts.
4.
Crests of standing mountain waves may be marked by stationary, lens-shaped clouds known as:
Correct Answer
A. Standing lenticular clouds.
Explanation
Standing lenticular clouds are stationary, lens-shaped clouds that can form on the crests of standing mountain waves. These clouds are formed when moist air is forced to rise over the mountain and condenses into a cloud. The unique shape of lenticular clouds is caused by the stable atmospheric conditions in which they form, with air flowing over the mountain and creating a series of waves. The stationary nature of these clouds is due to the fact that the air is moving up and down in a regular pattern, causing the cloud to remain in one position.
5.
What clouds have the greatest turbulence?
Correct Answer
C. Cumulonimbus.
Explanation
Cumulonimbus clouds have the greatest turbulence. These clouds are large and dense, extending vertically in the atmosphere. They are associated with thunderstorms and can reach great heights, often forming an anvil-shaped top. The strong updrafts and downdrafts within cumulonimbus clouds create turbulent conditions, leading to severe weather phenomena such as heavy rainfall, lightning, and strong winds.
6.
What cloud types would indicate convective turbulence?
Correct Answer
A. Towering cumulus clouds.
Explanation
Towering cumulus clouds indicate convective turbulence because they are formed by strong updrafts of warm air. These clouds are characterized by their vertical development and can reach great heights. The upward motion of air within these clouds creates turbulent conditions, which can be hazardous for aircraft. Cirrus clouds are high-altitude clouds composed of ice crystals and do not indicate convective turbulence. Nimbostratus clouds are associated with steady precipitation and do not typically indicate convective turbulence either. Therefore, the correct answer is towering cumulus clouds.
7.
Possible mountain wave turbulence could be anticipated when winds of 40 knots or greater blow:
Correct Answer
B. Across a mountain ridge and the air is stable.
Explanation
When winds blow across a mountain ridge, they can create mountain wave turbulence. This occurs when the airflow is disrupted by the mountain, causing waves of air to form on the leeward side. The stability of the air is an important factor in determining the intensity of the turbulence. If the air is stable, meaning it resists vertical motion, the turbulence is likely to be less severe. Therefore, when winds blow across a mountain ridge and the air is stable, there is a possibility of mountain wave turbulence.
8.
Every physical process of weather is accompanied by, or is the result of, a:
Correct Answer
C. Heat exchange.
Explanation
Every physical process of weather, such as the formation of clouds, precipitation, and wind patterns, involves the exchange of heat between different regions of the atmosphere. This heat exchange occurs due to variations in temperature, which create pressure differentials and cause air to move. Therefore, the correct answer is heat exchange.
9.
What causes variations in altimeter settings between weather reporting points?
Correct Answer
A. Unequal heating of the Earth's surface.
Explanation
The variations in altimeter settings between weather reporting points are caused by the unequal heating of the Earth's surface. As the Earth's surface heats up, the air above it also heats up, causing it to expand and become less dense. This results in a decrease in air pressure, which is reflected in the altimeter settings. Different areas of the Earth receive varying amounts of sunlight and heat, leading to variations in surface temperatures and subsequently, altimeter settings.
10.
What measures can be used to determine the stability of the atmosphere?
Correct Answer
A. Actual lapse rate.
Explanation
The actual lapse rate refers to the rate at which the temperature decreases with increasing altitude in the atmosphere. It is a measure of the stability of the atmosphere because it indicates how quickly the temperature changes with height. A steep lapse rate indicates instability, while a shallow lapse rate suggests stability. Therefore, the actual lapse rate can be used as a measure to determine the stability of the atmosphere.
11.
What would decrease the stability of an air mass?
Correct Answer
C. Warming from below.
Explanation
Warming from below would decrease the stability of an air mass because it causes the air to become less dense. As the air warms, it expands and becomes lighter, which reduces its ability to resist vertical motion. This can lead to the formation of convective currents and instability within the air mass. Cooling from below, on the other hand, would increase stability by making the air more dense and resistant to vertical motion. A decrease in water vapor may affect the humidity of the air mass, but it does not directly impact its stability.
12.
What is the characteristic of stable air?
Correct Answer
C. Stratiform clouds.
Explanation
Stable air is characterized by stratiform clouds. Stratiform clouds are flat and layered, covering a large area of the sky. They form in stable air when warm air is forced to rise slowly and gradually, causing the moisture to condense and form these clouds. Unlike cumulus clouds, which are puffy and indicate unstable air, stratiform clouds indicate calm and stable atmospheric conditions. Unlimited visibility and none of the above are not characteristics of stable air.
13.
Clouds, fog, or dew will always form when:
Correct Answer
C. Water vapor condenses.
Explanation
Clouds, fog, or dew will always form when water vapor condenses. When the air becomes saturated with water vapor and cannot hold any more, the excess moisture starts to condense into tiny water droplets or ice crystals, forming clouds, fog, or dew. This happens when the temperature of the air decreases or when the air comes into contact with a colder surface. As the water vapor cools and condenses, it transitions from a gas to a liquid or solid state, resulting in the formation of visible moisture in the form of clouds, fog, or dew.
14.
The amount of water vapor which air can hold depends on the:
Correct Answer
A. Air temperature.
Explanation
The amount of water vapor that air can hold is determined by its temperature. Warmer air has a higher capacity to hold water vapor compared to cooler air. As the temperature increases, the air molecules move faster, creating more space between them and allowing for more water vapor to be absorbed. Conversely, colder air has less space between molecules, limiting the amount of water vapor it can hold. Therefore, air temperature directly affects the maximum amount of water vapor that can be present in the air.
15.
What are the processes by which moisture is added to unsaturated air?
Correct Answer
B. Evaporation and sublimation.
Explanation
The correct answer is "Evaporation and sublimation." Evaporation is the process by which a liquid turns into a gas, adding moisture to the air. Sublimation, on the other hand, is the process by which a solid turns directly into a gas without passing through the liquid phase. Both of these processes contribute to adding moisture to unsaturated air. Heating and condensation are not the correct processes for adding moisture to unsaturated air.
16.
What is meant by the term 'dewpoint'?
Correct Answer
A. The temperature to which air must be cooled to become saturated.
Explanation
The term "dewpoint" refers to the temperature at which air needs to be cooled in order to become saturated. When air reaches its dewpoint temperature, it becomes saturated and cannot hold any more moisture, causing water vapor to condense and form dew. This is the point at which the air is at its maximum capacity for holding moisture, and any further cooling will result in the formation of dew or other forms of condensation.
17.
The greatest vortex strength occurs when the generating aircraft is:
Correct Answer
B. Heavy, clean, and slow.
Explanation
The greatest vortex strength occurs when the generating aircraft is heavy, clean, and slow. Vortex strength is directly related to the weight of the aircraft, with heavier aircraft generating stronger vortices. However, clean wings (without any external attachments or dirt) create more efficient vortices compared to dirty wings. Additionally, slower speeds allow for more time for the vortices to develop and strengthen. Therefore, heavy, clean, and slow aircraft will produce the greatest vortex strength.
18.
When taking off or landing at an airport where heavy aircraft are operating, one should be particularly alert to the hazards of wingtip vortices because this turbulence tends to?
Correct Answer
A. Sink into the flight path of aircraft operating below the aircraft generating the turbulence.
Explanation
Wingtip vortices are powerful rotating air currents that are created by the lift generated by an aircraft's wings. These vortices tend to sink into the flight path of aircraft operating below the aircraft generating the turbulence. This is a significant hazard because the turbulence caused by wingtip vortices can be strong enough to affect the control and stability of other aircraft flying in close proximity. Therefore, pilots should be particularly alert and take necessary precautions when operating in the vicinity of heavy aircraft to avoid the potential dangers posed by wingtip vortices.
19.
Which weather phenomenon is always associated with a thunderstorm?
Correct Answer
B. Lightning.
Explanation
Lightning is always associated with a thunderstorm because it is a natural electrical discharge that occurs during a storm. It is caused by the separation of positive and negative charges within a cloud, or between a cloud and the ground. The rapid movement of these charges creates a powerful electrical current, resulting in the visible flash of lightning. Therefore, whenever there is a thunderstorm, there will always be lightning accompanying it.
20.
Wingtip vortices are created only when an aircraft is?
Correct Answer
B. Developing lift.
Explanation
Wingtip vortices are created when an aircraft is developing lift. As an aircraft moves through the air, the wings generate lift by creating a pressure difference between the upper and lower surfaces. This pressure difference causes air to flow from the bottom of the wing to the top, creating a vortex at the wingtip. This vortex is more pronounced when the aircraft is developing a significant amount of lift, such as during takeoff or landing. Heavily loaded or operating at high airspeeds can contribute to the creation of wingtip vortices, but they are not the sole factors.
21.
When landing behind a large aircraft, the pilot should avoid wake turbulence by staying?
Correct Answer
A. Above the large aircraft's final approach path and landing beyond the large aircraft's touchdown point.
Explanation
The pilot should avoid wake turbulence by staying above the large aircraft's final approach path and landing beyond the large aircraft's touchdown point. This is because wake turbulence is created by the wings of an aircraft as it generates lift. The vortices created by the wings can linger in the air for several minutes after the aircraft has passed. By staying above the large aircraft's final approach path, the pilot ensures that they are flying at a higher altitude and thus avoiding the wake turbulence. Additionally, landing beyond the large aircraft's touchdown point ensures that the pilot does not encounter the wake turbulence during their landing.
22.
When departing behind a heavy aircraft, the pilot should avoid wake turbulence by maneuvering the aircraft?
Correct Answer
C. Above and upwind from the heavy aircraft.
Explanation
When departing behind a heavy aircraft, the pilot should maneuver the aircraft above and upwind from the heavy aircraft to avoid wake turbulence. Wake turbulence is the disturbance in the air caused by the passage of an aircraft, and it can be hazardous for smaller aircraft flying behind larger ones. By flying above and upwind from the heavy aircraft, the pilot can minimize the risk of encountering the wake turbulence and maintain a safe distance. Flying below or downwind from the heavy aircraft would increase the chances of encountering the turbulence and pose a potential danger.
23.
What feature is normally associated with the cumulus stage of a thunderstorm?
Correct Answer
B. Continuous updraft.
Explanation
The cumulus stage of a thunderstorm is characterized by a continuous updraft. During this stage, warm air rises rapidly, creating a vertical column of air that feeds the storm. This updraft allows the storm to grow and develop, leading to the formation of the anvil-shaped cloud characteristic of a mature thunderstorm. Frequent lightning is more commonly associated with the mature stage of a thunderstorm, while a roll cloud is a horizontal, tube-shaped cloud that can sometimes form along the leading edge of a thunderstorm. Therefore, the correct answer is continuous updraft.
24.
Which weather phenomenon signals the beginning of the mature stage of a thunderstorm?
Correct Answer
C. Precipitation beginning to fall.
Explanation
The correct answer is precipitation beginning to fall. This is because when precipitation starts to fall from a thunderstorm, it indicates that the storm has reached its mature stage. The mature stage is characterized by the presence of heavy rain, hail, and strong winds. The precipitation is a result of the updrafts and downdrafts within the storm, which cause moisture to condense and fall as rain or other forms of precipitation. Therefore, the beginning of precipitation marks the transition from the developing stage to the mature stage of a thunderstorm.
25.
Which meteorological instrument is primarily used to measure the vertical profile of temperature, humidity, and pressure in the atmosphere?
Correct Answer
C. Radiosonde
Explanation
C is correct because a radiosonde is a meteorological instrument used to collect data on temperature, humidity, and pressure as it ascends through the atmosphere, providing a vertical profile. The barometer measures atmospheric pressure, the anemometer measures wind speed, and the thermometer measures temperature at a specific point, but none provide a vertical atmospheric profile.
26.
Thunderstorms reach their greatest intensity during the:
Correct Answer
B. Mature stage.
Explanation
During the mature stage of a thunderstorm, the updraft and downdraft within the storm are at their strongest. This is when the storm is fully developed and most intense, with heavy rain, strong winds, lightning, and even hail. The mature stage is characterized by the presence of a strong updraft that sustains the storm and allows it to continue to grow and intensify. Therefore, the correct answer is the mature stage.
27.
The boundary between two different air masses is referred to as a:
Correct Answer
A. Front.
Explanation
The boundary between two different air masses is referred to as a front. A front is a transition zone where two air masses with different properties, such as temperature, humidity, and density, meet. These air masses do not mix easily due to their contrasting characteristics, resulting in the formation of a front. Fronts are often associated with changes in weather conditions and can lead to the development of clouds, precipitation, and other atmospheric phenomena. Frontolysis and frontogenesis are terms used to describe the weakening or strengthening of a front, respectively. However, in this case, the correct answer is simply front.
28.
One of the most easily recognized discontinuities across a front is:
Correct Answer
A. A change in temperature.
Explanation
A front is a boundary between two air masses with different characteristics. One of the most easily recognized discontinuities across a front is a change in temperature. As warm and cold air masses collide, the temperature abruptly changes, creating a noticeable contrast. This change in temperature is often accompanied by other weather phenomena such as cloud formation, precipitation, and changes in wind direction. However, while an increase in cloud coverage and relative humidity can be associated with a front, they are not the most easily recognized discontinuities. Therefore, the correct answer is a change in temperature.
29.
One weather phenomenon which will always occur when flying across a front is a change in the:
Correct Answer
A. Wind direction.
Explanation
When flying across a front, a change in wind direction will always occur. Fronts are the boundaries between different air masses with different temperature, humidity, and pressure. As an aircraft crosses a front, it encounters the transition zone between these air masses, resulting in a change in wind direction. This change is typically associated with a change in weather conditions, such as shifts in temperature, cloud cover, and precipitation. Therefore, the correct answer is wind direction.
30.
Where does wind shear occur?
Correct Answer
B. At all altitudes, in all directions.
Explanation
Wind shear refers to the sudden change in wind speed or direction over a short distance. It can occur at all altitudes and in all directions. Wind shear can be caused by various factors such as temperature variations, terrain features, and atmospheric conditions. It is commonly experienced by pilots during takeoff and landing, but it can also occur at higher altitudes and affect the stability and performance of aircraft. Therefore, the correct answer is that wind shear occurs at all altitudes and in all directions.
31.
What situation is most conducive to the formation of radiation fog?
Correct Answer
A. Warm, moist air over low, flatland areas on clear, calm nights.
Explanation
Radiation fog is formed when the ground cools down rapidly at night, causing the air near the surface to cool as well. This cooling leads to the condensation of water vapor in the air, forming fog. In this situation, warm, moist air over low, flatland areas is more likely to cool down quickly due to the absence of obstacles that could trap heat. Clear, calm nights also prevent mixing of the air, allowing for the formation of fog.
32.
In which situation is advection fog most likely to form?
Correct Answer
B. An Airmass moving inland from the coast in winter.
Explanation
Advection fog occurs when a warm, moist air mass moves over a colder surface. In this case, an airmass moving inland from the coast in winter fits this description. As the warm, moist air moves over the colder land, it cools down and reaches its dew point, causing the water vapor to condense and form fog. The other options do not involve the movement of a warm, moist air mass over a colder surface, so they are less likely to result in advection fog formation.
33.
If there is thunderstorm activity in the vicinity of an airport at which you plan to land, which hazardous atmospheric phenomenon might be expected on the landing approach?
Correct Answer
A. Wind-shear turbulence.
Explanation
When there is thunderstorm activity in the vicinity of an airport, it can create hazardous atmospheric conditions, including wind-shear turbulence. Wind-shear turbulence refers to sudden changes in wind speed and direction, which can be dangerous during landing approach as it can cause the aircraft to lose control or experience sudden shifts in altitude. Steady rain, although it may reduce visibility, is not specifically associated with thunderstorms and does not pose as much of a threat during landing. Precipitation static refers to static electricity buildup on the aircraft due to precipitation, but it is not directly related to thunderstorm activity. Therefore, the correct answer is wind-shear turbulence.
34.
One in-flight condition necessary for structural icing to form is:
Correct Answer
B. Visible moisture.
Explanation
Visible moisture is necessary for structural icing to form during flight. Structural icing occurs when moisture in the air, such as water droplets or ice crystals, comes into contact with the aircraft's surfaces and freezes. This can happen when the temperature is below freezing and there is visible moisture present, such as clouds, fog, or precipitation. Without visible moisture, there is no source of water to freeze and cause structural icing. Stratiform clouds and small temperature/dewpoint spread are not necessarily indicative of visible moisture, so they are not the correct answers.
35.
Under which condition will pressure altitude be equal to true altitude?
Correct Answer
B. When standard atmospHeric conditions exist.
Explanation
When standard atmospheric conditions exist, the pressure altitude will be equal to the true altitude. Standard atmospheric conditions refer to a specific set of conditions defined by the International Civil Aviation Organization (ICAO), which include a temperature of 15 degrees Celsius at sea level and a pressure of 29.92 inches of mercury (Hg). In these conditions, the altimeter reading will accurately reflect the true altitude of the aircraft above sea level.
36.
Under what condition is pressure altitude and density altitude the same value?
Correct Answer
A. At standard temperature.
Explanation
Pressure altitude is defined as the altitude in the standard atmosphere where the atmospheric pressure is equal to the measured pressure. Density altitude, on the other hand, takes into account the temperature variations from the standard atmosphere. At standard temperature, the temperature is equal to the temperature in the standard atmosphere, and therefore the pressure altitude and density altitude will be the same. This is because the temperature is not deviating from the standard, so the density of the air remains the same.
37.
If a flight is made from an area of low pressure into an area of high pressure without the altimeter setting being adjusted, the altimeter will indicate?
Correct Answer
C. Lower than the actual altitude above sea level.
Explanation
When a flight is made from an area of low pressure into an area of high pressure without adjusting the altimeter setting, the altimeter will indicate a lower altitude than the actual altitude above sea level. This is because the altimeter measures pressure, and in a high-pressure area, the altimeter will interpret the higher pressure as a higher altitude. Therefore, the altimeter reading will be lower than the actual altitude above sea level.
38.
Which condition would cause the altimeter to indicate a lower altitude than true altitude?
Correct Answer
A. Air temperature warmer than standard.
Explanation
When the air temperature is warmer than standard, the air density decreases. This decrease in air density causes the altimeter to indicate a lower altitude than the true altitude. This is because the altimeter measures altitude based on the pressure of the surrounding air, and when the air density is lower, the pressure exerted on the altimeter is also lower, resulting in a lower altitude reading.
39.
Which factor would tend to increase the density altitude at a given airport?
Correct Answer
A. An increase in ambient temperature.
Explanation
An increase in ambient temperature would tend to increase the density altitude at a given airport. Density altitude is the altitude at which an aircraft "feels" it is flying due to the density of the air. As temperature increases, air molecules spread out and become less dense, resulting in a higher density altitude. This can affect aircraft performance, as it reduces engine power and lift, making takeoffs and landings longer and increasing the risk of stalls.
40.
What conditions are necessary for the formation of thunderstorms?
Correct Answer
B. High humidity, lifting force, and unstable conditions.
Explanation
Thunderstorms require specific conditions to form. High humidity is necessary because it provides the moisture needed for the development of clouds and precipitation. A lifting force is required to lift the warm, moist air upwards, allowing it to cool and condense into clouds. Unstable conditions are also necessary, as they create an environment where the warm air can rise rapidly and form powerful updrafts. These updrafts then interact with the surrounding air to create the characteristic thunderstorm features such as lightning, thunder, and heavy rainfall. Therefore, the correct answer is high humidity, lifting force, and unstable conditions.