PCOC Vehicle Systems and Operations 4

Question 1

What is the role of the lower unit on an outboard motor?

Accepted Answer

It houses the gearbox and propeller shaft, transmitting power to the propeller

Answer

It contains the fuel injection system and carburetor

Answer

It holds the electric starter motor and battery

Answer

It regulates the engine's cooling water intake valve

Question 2

What is cavitation in the context of a boat propeller?

Accepted Answer

Formation of vapor bubbles around the propeller blades that collapse and cause damage

Answer

The vibration caused by a bent or damaged propeller blade

Answer

Engine stalling caused by water entering the fuel system

Answer

A reduction in thrust from running the engine at too low an RPM

Question 3

On a twin-engine vessel, how is backing and turning typically achieved?

Accepted Answer

By running one engine forward and one engine in reverse simultaneously

Answer

By using the rudder while both engines are in neutral

Answer

By cutting both engines and using the drift of the current

Answer

By applying the electric trim tabs asymmetrically

Question 4

What is the function of a marine battery switch (main battery switch)?

Accepted Answer

To connect or disconnect the battery from the electrical system

Answer

To switch between fuel tanks when one runs low

Answer

To activate the bilge pump in an emergency

Answer

To regulate charging voltage from the alternator

Question 5

Which condition would cause a boat engine to overheat most quickly?

Accepted Answer

A failed or damaged water pump impeller blocking coolant flow

Answer

Running the engine at low throttle in calm water

Answer

Using a propeller with too low a pitch

Answer

Having a slightly low oil level in the engine

Question 6

What does 'trim angle' on a power boat primarily affect?

Accepted Answer

Fuel efficiency, handling, and top speed by adjusting the bow's angle to the water

Answer

The depth to which the anchor sets on the seabed

Answer

The rate at which the bilge fills during rain

Answer

The voltage output of the engine's alternator

Question 7

What is the purpose of the sacrificial anode (zinc) attached to a boat's lower unit?

Accepted Answer

To corrode preferentially and protect metal components from galvanic corrosion

Answer

To add ballast weight for hull stability in rough seas

Answer

To improve the magnetic compass reading accuracy

Answer

To act as a ground for the vessel's electrical system