4.1 What is the function of the computerised diagnostic scanner used on a motor vehicle?
A - NSC Mechanical Technology Automotive - Question 4 - 2020 - Paper 1
Question 4
4.1 What is the function of the computerised diagnostic scanner used on a motor vehicle?
A. To scan whether the engine leaks gases from the cylinder during the indu... show full transcript
Worked Solution & Example Answer:4.1 What is the function of the computerised diagnostic scanner used on a motor vehicle?
A - NSC Mechanical Technology Automotive - Question 4 - 2020 - Paper 1
Step 1
What is the function of the computerised diagnostic scanner used on a motor vehicle?
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Answer
The correct option is C. A computerized diagnostic scanner is designed to scan all systems in the vehicle, enabling diagnostics and adjustments of various components to ensure optimal performance.
Step 2
Which ONE of the following pieces of equipment is used to test the crankcase gases?
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Answer
The correct option is B. The gas analyzing tester is specifically used to determine the composition of gases emitted from the crankcase, which aids in diagnosing engine issues.
Step 3
What is the volumetric efficiency of a centrifugal blower?
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Answer
The correct option is C. Volumetric efficiency refers to the ability of the blower to fill the cylinder with air above the atmospheric pressure, which affects the performance of the engine.
Step 4
What is the problem of unbalancing that causes crankshaft vibrations?
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Answer
The correct option is B. If the crankshaft is not balanced, it leads to vibrations, which can cause severe damage to the engine over time.
Step 5
Which ONE of the following is an important method used to increase the compression ratio of an engine?
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Answer
The correct option is A. Fitting a thinner gasket between the cylinder block and the cylinder head is a common method to increase the compression ratio, enhancing engine performance.
Step 6
What does the symbol X in FIGURE 4.6 indicate?
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Answer
The correct option is A. The symbol X in the figure typically indicates the compression length, which is a critical measurement in engine design.
Step 7
What will be the brake power of the engine if the engine delivers a mechanical efficiency of 83.34% with 60 kW indicated power?
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Answer
The correct option is D. The brake power can be calculated as Brake Power = Indicated Power × Mechanical Efficiency = 60 kW × 0.8334, leading to approximately 50 kW.
Step 8
What type of test is conducted with the equipment shown in FIGURE 4.8?
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Answer
The correct option is C. The equipment is primarily used for testing for fuel leaks, essential for ensuring the safety and efficiency of the vehicle.
Step 9
Which ONE of the following is an advantage of an electrical fuel pump in a motor vehicle?
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Answer
The correct option is C. One significant advantage of electrical fuel pumps is their low operation noise, which contributes to a quieter vehicle experience.
Step 10
What type of tyre wear is shown in FIGURE 4.10?
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Answer
The correct option is A. Feathered-edged wear is commonly seen on tyres due to misalignments or improper inflation.
Step 11
What type of drive is the outcome when the planet carrier is locked for a double epicyclic gear?
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Answer
The correct option is A. Locking the planet carrier results in a first or low gear output, affecting the torque delivered.
Step 12
Which gear system is shown in FIGURE 4.12?
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Answer
The answer cannot be determined as Figure 4.12 has not been provided.
Step 13
What will be the speed of a driven gear if the gear ratio of a gear train is given as 5 : 1 and the drive gear rotates at 500 r/min?
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Answer
The correct option is A. The speed of the driven gear can be found using the formula: Speed of Driven Gear = (500 r/min) × (5) = 2 500 r/min.
Step 14
Which ONE of the following is the function of the rotor assembly in an alternator charging system?
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Answer
The correct option is C. The rotor assembly provides a rotary electro-magnet, which is essential for generating alternating current in an alternator.
