Various options are provided as possible answers to the following questions - NSC Mechanical Technology Automotive - Question 4 - 2019 - Paper 1
Question 4
Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A–D) next to the question numbers (4.1 to 4... show full transcript
Worked Solution & Example Answer:Various options are provided as possible answers to the following questions - NSC Mechanical Technology Automotive - Question 4 - 2019 - Paper 1
Step 1
4.1 The purpose of conducting a compression test for an internal combustion engine is to test the pressure in the …
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Answer
The correct answer is A: cylinder. A compression test assesses the pressure within the engine's cylinders, essential for determining the engine's health.
Step 2
4.2 Which ONE of the following equipment is used to test the exhaust gases of an internal combustion engine?
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Answer
The correct answer is D: Combustion analyser. This equipment specifically measures the components of the exhaust gases, providing insights into the combustion efficiency.
Step 3
4.3 The function of the crankshaft in an internal combustion engine is to convert the reciprocating motion of the piston into a … motion.
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Answer
The correct answer is C: vertical. The crankshaft's role is to convert the linear movement of the piston into circular motion that ultimately drives the vehicle.
Step 4
4.4 Which ONE of the following firing orders is applicable to a V6 internal combustion engine?
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Answer
The correct answer is A: 1-5-3-6-2-4. This firing order ensures optimal engine balance and smooth power delivery.
Step 5
4.5 An important factor that determines the thermal efficiency of an engine is the …
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Answer
The correct answer is D: valve opening. The timing and extent of valve openings play a crucial role in maximizing engine efficiency.
Step 6
4.6 The total volume that the piston displaces when the piston moves upwards, is referred to as the …
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Answer
The correct answer is D: swept volume. This term defines the volume displaced by the piston during its stroke.
Step 7
4.7 What will be the mechanical efficiency of an engine if the brake power of the engine is 65 kW and the indicated power is 80 kW?
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Answer
To find the mechanical efficiency, use the formula:
4.8 Which ONE of the following safety procedures must be adhered to when a cylinder leakage tester is used on an internal combustion engine?
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Answer
The correct answer is B: Do not exceed the prescribed pressure in the cylinder. This safety measure prevents damage to the engine components.
Step 9
4.9 Which ONE of the following is the cause of low oil pressure in an internal combustion engine?
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Answer
The correct answer is D: Too large engine capacity. A higher engine capacity can lead to lower oil pressure, affecting lubrication.
Step 10
4.10 Which ONE of the following statements defines the caster angle on a motor vehicle’s suspension?
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Answer
The correct answer is B: The angle formed when the steering axis is viewed from the side of the king-pin as seen from the front. This angle affects vehicle handling and stability.
Step 11
4.11 Which ONE of the following terms describes the condition when the impeller of a torque converter rotates at maximum speed and the turbine is almost stationary (standing still)?
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Answer
The correct answer is C: Stall speed. This term refers to the condition where the impeller's speed exceeds the turbine's speed, resulting in the turbine not rotating.
Step 12
4.12 Which ONE of the outside gear is in an epicyclic (planetary-) gear train?
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Answer
The correct answer is B: Ring gear. The ring gear is typically the stationary part in a planetary gear system.
Step 13
4.13 What does the abbreviation MAP stand for in terms of the air-induction sensor as part of the engine control system?
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Answer
The correct answer is A: Main absolute pressure. This sensor measures the absolute air pressure in the intake manifold.
Step 14
4.14 Which ONE of the following is the purpose of the brake bands in the three-speed automatic gearbox?
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Answer
The correct answer is A: To drive the sun gear from the planetary gear set. This function is crucial for allowing the gearbox to shift between different speeds.
