Power Mechanics P1 Questions - Wisdom Pre-Mock Form 4 Exams 2021/2022

Instructions to Candidate’s

• Write your Name, Index Number, Class and Admission Number in the spaces provided above.
• Answer all the questions in section A in the spaces provided.
• Answer question 11 and any other three questions in section B.

QUESTIONS

SECTION A (40 Marks)
Answer all the questions in this section in the spaces provided.

1. State four uses of internal combustion engine. (4 marks)
2. State two safety precautions that should be observed when using each of the following tools.
   1. Hammer (2 marks)
   2. Spanner (2 marks)
3.                                  
   1. Give two reasons for allowing materials. (2 marks)
   2. Explain the functions of the following engine components. (2 marks)
      1. Spark plug
      2. Recoil starter
4.                    
   1. Draw the following types of bearings.
      1. Flanged blind bearing. (1 mark)
      2. Plain bush (1 mark)
   2. Differentiate between a gasket and a seal in terms of their uses. (2 marks)
5. The table below shows components that are found in an engine cam shaft. State the function of each. (4 marks)
6.                              
   1. Differentiate between a lean mixture and a rich mixture. (2 marks)
      

      Component	Function
      Cam lobes
      Eccentric cam
      Spiral gear
      Bearing journals

   2. Explain the following types of an engine. (3 marks)
      1. Over square
      2. Under square
      3. Square
7. List four causes of oil contamination in an engine. (4 marks)
8. The following is a component found in an engine
   
   
   1. Name the component:(1 mark)
   2. State in which system it is found:1 mark)
   3. Name that parts labelled A and B;
      A ___________________________ (1 mark)
      B___________________________ (1 mark)
9.                        
   1. Explain two reasons why an alternator is preferred to a d.c generator. (2 marks)
   2. Name the component of an labeled B below. (1 mark)
      
      
      1. State the use of the part labeled A. (1 mark)
10. Sketch, in 1st Angle orthographic projection, the F.E. and E.E. of the shaped block shown. (3 marks)
    

SECTION B: (60 MARKS)
Answer question 11 and any other three questions from this section.

11. The figure below shows components drawn in fist angle orthographic projection. On A3 paper provided draw full scale the isometric view of the object. (15 marks)
    
12.                            
    1. State two functions of a soldering flux. (2 marks)
    2. State three properties of a good soldering flux. (3 marks)
    3. Explain the difference between welding and soldering. (2 marks)
    4. Study the diagram below.
       
       
       1. Name the parts labeled. (5 marks)
          A______________________
          C_______________________
          D_______________________
          G_______________________
          H_______________________
       2. Explain the function of the following parts. (3 marks)
          B_______________________
          E_______________________
          F_______________________
13. The diagram below shows a diesel fuel system with parts labeled A to F.
    
    
    1. State the name and function of the parts and fill your and the table below;(10 marks)
       

       COMPONENT	NAME	FUNCTION
       B
       C
       D
       E
       F

    2. State two functions of a fuel tank cap. (2 marks)
    3. List three types of diesel fuel filters. (3 marks)
14.                      
    1. Draw a neat diagram of a dry plate clutch assembly and label at least four parts.(6 marks)
    2. Explain how the above assembly functions;
       1. During engagement (3 marks) _____________________
       2. During disengagement (3 marks) ______________________
    3. Explain the effect of the following in a clutch assembly. (3 marks)
       1. Presence of oil on the friction plate
       2. Weak thrust spring
       3. No cushion springs on the clutch plate
15. The size of a four cylinder combustion engine is given by;
    - Bore 90mm
    - Stroke 90mm
    - Clearance volume 71.6cc
    Determine the following;
    1. The engine capacity to the nearest cc. (5 marks)
    2. Compression ratio to one decimal place. (4 marks)
    3. Explain if the engine is spark ignition or compression ignition engine.(2 marks)
    4. Explain the following terms as used in engine description. (4 marks)
       • Model 
       • Make
       • Capacity
       • Serial number