midterm quiz 1 nav 1

What is the main function of an echo-sounder?

• To accurately determine the ship's position

• To measure the depth of the water below the ship

• To locate and identify objects on the seabed

• To communicate with underwater vehicles

What does the acronym SONAR stand for?

• Sound Observation and Ranging

• Sound Navigation and Ranging

• Sonar Operations and Reporting

• Sounding Navigation and Recording

Which physicist is credited with inventing echo-sounding?

• Alexander Graham Bell

• Alexander Behm

• Thomas Edison

• Robert Fulton

What is the purpose of the transducer in the echo-sounder?

• It records the depth on a paper chart

• It converts sound waves to electrical signals

• It generates the electrical pulses for transmission

• It amplifies the returning echo signal

What is the approximate speed of sound in water?

• 1500 meters per second

• 1000 meters per second

• 500 meters per second

• 2000 meters per second

How is the depth calculated by an echo-sounder?

• Using time and the ship’s speed over ground

• Using the time interval and sound speed in water

• Using the frequency of the returning sound signal

• Using the amplitude of the initial sound pulse

What is a common cause of 'cross noise' in an echo-sounder?

• A very low gain setting on the receiver

• A malfunctioning transducer element

• Air bubbles passing over the transducer

• The ship being in a state of trim or heel

What is the function of the receiver component?

• It converts electrical pulses into sound waves

• It generates the high-voltage electrical pulses

• It processes and amplifies the returned signal

• It displays the depth reading visually on a screen

What is a common cause of 'false echoes'?

• An incorrect zero line adjustment

• Multiple reflections from the seabed

• The stylus speed being set incorrectly

• The presence of a 'Pythagoras error'

What is UKC short for in marine navigation?

• Underwater Keel Clearance

• Under-Keel Compensation

• Ultimate Keel Coefficient

• Under-Keel Clearance