This question posed a big problem to the candidates as they could not give
the required responses to the various parts of the question. The required responses are:
(a) functions of a poppet valve include:
- make a gas-tight seal with its ports when closed;
- offer no opposition of charge into the cylinder when opened;
- operate with minimum friction;
- operate with simple mechanism, and
- open to allow the escape of burnt gases.
(b) The correct sketch of a poppet valve is given below.
(c) Three parts of a wheel are the
tyre;
rim and
tube.
