# Competence 3 (Deck)

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| By Catherine Halcomb
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Catherine Halcomb
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Questions: 10 | Attempts: 3,005

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• 1.

### Which ARPA data should you use in order to determine if a close quarters situation will develop with a target vessel?

• A.

Relative track information

• B.

Predicted time of CPA

• C.

Initial range of acquisition

• D.

Set and drift of the current

A. Relative track information
Explanation
The relative track information provides data about the direction and speed of the target vessel in relation to your own vessel. By analyzing this information, you can determine if the target vessel is on a course that will bring it into close quarters with your vessel. Therefore, the relative track information is crucial in determining if a close quarters situation will develop with a target vessel.

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• 2.

### This may occur when a strong echo is received from another ship at close range.

• A.

Clutter

• B.

Diffraction

• C.

False echo

• D.

Multiple echoes

D. Multiple echoes
Explanation
Multiple echoes can occur when a strong echo is received from another ship at close range. This means that the sound waves emitted by the ship bounce off the other ship and return to the original ship, creating multiple echoes. These echoes can interfere with the original signal, causing confusion and making it difficult to accurately interpret the received information. Therefore, multiple echoes can be a result of strong echoes being reflected back from nearby objects or ships.

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• 3.

### The description beside an illustration on a chart would mean a:

• A.

• B.

• C.

• D.

Explanation
A radar transponder beacon refers to a device that emits a signal in response to a radar signal, enabling the radar system to detect and locate its position accurately. This type of beacon is commonly used in aviation and marine applications to enhance safety and navigation. It assists radar systems by providing a clear and distinct signal that can be easily identified and tracked.

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• 4.

### What is dangerous with operating the ARPA in mixed mode over time?

• A.

Forgetting that this actually is a mixed mode

• B.

The ARPA symbols becomes unstable

• C.

• D.

The target warning are no longer relevnat

A. Forgetting that this actually is a mixed mode
Explanation
Operating the ARPA in mixed mode can be dangerous if one forgets that it is in mixed mode. This is because the operator may not be aware of the limitations and specific procedures associated with mixed mode operation. This can lead to errors, incorrect interpretations of data, and potentially dangerous situations. It is important for operators to always be aware of the mode they are operating in to ensure the safe and effective use of the ARPA system.

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• 5.

### When the gyro-pilot is used for steering, what control is a adjusted to compensate for varying sea conditions?

• A.

• B.

Rudder control

• C.

• D.

Sea control

B. Rudder control
Explanation
When the gyro-pilot is used for steering, the control that is adjusted to compensate for varying sea conditions is the rudder control. The rudder control is responsible for changing the direction of the vessel by adjusting the angle of the rudder, which helps to maintain stability and control in different sea conditions. By adjusting the rudder control, the gyro-pilot can effectively steer the vessel and compensate for any changes or disturbances caused by varying sea conditions.

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• 6.

### What is the purpose of the anti-clutter "sea" control on the radar?

• A.

Reduce the sea echoes

• B.

Remove wash return from the propeller

• C.

Increase brilliance of large echoes against sea

• D.

Intensify sea return

A. Reduce the sea echoes
Explanation
The purpose of the anti-clutter "sea" control on the radar is to reduce the sea echoes. This control helps to filter out the unwanted clutter caused by the radar signals bouncing off the surface of the sea. By reducing the sea echoes, the radar can provide a clearer and more accurate representation of other targets or echoes of interest, such as ships or landmasses. This improves the radar's ability to detect and track objects in the presence of clutter, enhancing its overall performance and effectiveness.

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• 7.

### What does RADAR stand for?

• A.

• B.

• C.

• D.

Explanation
RADAR stands for Radio detection and ranging. This acronym accurately describes the technology used in RADAR systems, which involves the detection of objects using radio waves and determining their range or distance from the source. By emitting radio waves and analyzing the echoes that bounce back from objects, RADAR systems can detect and track the presence, location, and movement of objects, such as aircraft, ships, or weather patterns.

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• 8.

### The components that generate the radio-frequency energy in the form of short powerful pulse is the:

• A.

• B.

Magnetron

• C.

Modulator

• D.

Indicator

B. Magnetron
Explanation
The correct answer is Magnetron. A magnetron is a component that generates radio-frequency energy in the form of short powerful pulses. It is commonly used in microwave ovens to produce the electromagnetic waves that heat up the food. The magnetron works by using a high voltage to accelerate electrons towards a series of resonant cavities, where they interact with a magnetic field to generate the desired radio-frequency energy. This energy is then emitted as a short, powerful pulse, which is essential for efficient heating in microwave ovens.

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• 9.

### With regards to ARPA, what does the "lost target" warning tell?

• A.

Display failure

• B.

• C.

Computer failure

• D.

Target can no longer be plotted

D. Target can no longer be plotted
Explanation
The "lost target" warning in ARPA indicates that the target can no longer be plotted. This means that the system is no longer able to track or display the position and movement of the target. This could be due to various reasons such as the target going out of range, being obscured by obstacles, or the target itself being lost or no longer detectable by the radar system.

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• 10.

### When using the ARPA in heavy rain, which action should you take?

• A.

Increase the STC setting to reduce close-in spurious signals.

• B.

Increase the radar gain to pick up weak echoes through the rain.

• C.

Navigate as though the effective range of the radar has been reduced.

• D.

Increase the range of the inner and outer guard rings.

C. Navigate as though the effective range of the radar has been reduced.
Explanation
When using the ARPA (Automatic Radar Plotting Aid) in heavy rain, it is essential to navigate as though the effective range of the radar has been reduced. Heavy rain can significantly affect the radar's performance by reducing its range and causing weaker echoes. Therefore, it is crucial to be cautious and adjust navigation accordingly, taking into account the reduced range of the radar. This will help ensure the safety of the vessel and its crew by accounting for the limitations imposed by the heavy rain on the radar's effectiveness.

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