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 …
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The purpose of conducting a compression test for an internal combustion engine is to test the pressure in the cylinder to ensure that it can build sufficient pressure for efficient combustion.
Step 2
4.2 Which ONE of the following equipment is used to test the exhaust gases of an internal combustion engine?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The equipment used to test the exhaust gases of an internal combustion engine is a Combustion analyser, which measures the composition of exhaust gases to assess engine performance.
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.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The function of the crankshaft in an internal combustion engine is to convert the reciprocating motion of the piston into a rotary motion, allowing the engine to generate power.
Step 4
4.4 Which ONE of the following firing orders is applicable to a V6 internal combustion engine?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The firing order applicable to a V6 internal combustion engine is 1-4-2-6-3-5, which helps in smooth engine operation and minimizes vibration.
Step 5
4.5 An important factor that determines the thermal efficiency of an engine is the …
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
An important factor that determines the thermal efficiency of an engine is the design of the intake manifold, as it influences the air-fuel mixture and the engine's combustion process.
Step 6
4.6 The total volume that the piston displaces when the piston moves upwards, is referred to as the …
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The total volume that the piston displaces when it moves upwards is referred to as the swept volume, which is essential for calculating engine capacity.
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?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The mechanical efficiency of the engine can be calculated using the formula:
ext{Efficiency} = rac{ ext{Brake Power}}{ ext{Indicated Power}} imes 100
Thus, the efficiency is:
rac{65 ext{ kW}}{80 ext{ kW}} imes 100 = 81.25 ext{%}
Step 8
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?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
When using a cylinder leakage tester, the safety procedure that must be adhered to is to use water to remove dust around the spark plug area for safe testing.
Step 9
4.9 Which ONE of the following is the cause of low oil pressure in an internal combustion engine?
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The cause of low oil pressure in an internal combustion engine could be worn oil pump components, which affect oil circulation and engine lubrication.
Step 10
4.10 Which ONE of the following statements defines the caster angle on a motor vehicle’s suspension?
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The caster angle on a motor vehicle’s suspension is defined as the angle formed between the perpendicular line and the centre line of the king-pin as seen from the front.
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)?
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The condition when the impeller of a torque converter rotates at maximum speed while the turbine is almost stationary is referred to as stall speed.
Step 12
4.12 Which gear is the outside gear in an epicyclic (planetary-) gear train?
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In an epicyclic (planetary) gear train, the outside gear is referred to as the annulus, which surrounds the planet gears.
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?
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The abbreviation MAP stands for Manifold Absolute Pressure, which measures the pressure within 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?
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The purpose of the brake bands in the three-speed automatic gearbox is to hold the secondary sun gear and the planetary gear set, ensuring proper transmission of power.
