Ordinary level 2026 North West mock mechanical technology 1

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1. An example of Internal Combustion engine is;

• A. reciprocation engines

• B. rotary gas turbine

• C. wankel engines

• D. steam engine

2. The cylinder head gasket shown in figure 1

(Figure 1 shows a multi-layered metal gasket with six cylinder openings)

• A. acts as seal

• B. permit water to circulate to radiator

• C. provides combustion

• D. cool down the engine

3. In an inline cylinder straight engine with a firing order of 1432, cylinder 1 is doing compression. Cylinder 2 will be doing

• A. power

• B. induction

• C. exhaust

• D. compression

4. As compared to the petrol engine, the diesel engine has

• A. high speed engine

• B. high compression ratio

• C. low compression ratio

• D. equal fuel consumption

5. Choose from below the sensor that when it fails, will causes a misfire due to incorrect air/fuel ratio.

• A. Engine sensor

• B. Lambda sensor

• C. MAF sensor

• D. Crankshaft sensor

6. The role of a supercharging in a diesel engine is to:

• A. supplying fuel at a high pressure

• B. supplying air at a density greater than atmospheric

• C. cooling the exhaust gases

• D. increase the speed of the piston

7. Which of these is essential for combustion reaction to occur?

• A. Fuel only

• B. Oxygen only

• C. Water and oxygen

• D. Fuel, oxygen and heat

8. Identify the component in figure 2.

(Figure 2 shows an exhaust component with chemical symbols $HC+CO+NO2$ entering and $CO2+H2O+N2$ exiting)

• A. Oil pan

• B. ECU

• C. Catalytic converter

• D. Exhaust manifold

9. What is valve overlap?

• A. Period when both valves are open

• B. Time both valves are close

• C. Period exhaust valve stays open

• D. Time intake valve stays close

10. Identify the adjustment being carried out in figure 3.

(Figure 3 shows a feeler gauge being used between a rocker arm and a valve stem)

• A. Rocker clearance

• B. Valve timing

• C. Camshaft lobe adjustment

• D. Valve clearance

11. A 4-cylinder engine has bore of 8 cm and 9 cm as stroke: Determine the engine displacement.

• A. $1809.56\text{ cm}^3$

• B. $452.39\text{ cm}^3$

• C. $68\text{ cm}^3$

• D. $288\text{ cm}^3$