Most candidates who attempted this question could not provide the required responses to the various parts of the question.  The required responses to the various parts of the question are:

(a)       (i)         Splash lubrication system.
            (ii)        U  – cylinder block or engine block  
                        V  – piston
                        W – connecting rod or con rod
                        X  – dipper or oil dipper
            (iii)       dip stick.

(b)       The demerits of the lubrication system are:

• no pressure for effective lubrication;
• no oil filter and therefore lubricating oil is usually contaminated;
• no uniform lubrication;

(c)        The principle of operation of the splash lubrication system is as follows:

As the crankshaft revolves, the dipper which is attached to the end of the connecting rod big end scoops lubricating oil from the sump and splashes it onto the upper parts of the engine such as the cylinder wall.  The lubricating oil on the wall is therefore scrapped back into the sump by the oil control ring.