Diploma CET Mechanical Question Paper

21) When the piston is at Top Dead Centre, the volume above the piston in the combustion chamber is

Answer is:

Clearance volume

When the piston is at Top Dead Centre, the volume above the piston in the combustion chamber is

22) The Calorific value of Diesel is about

Answer is:

42.5 MJ/kg

23) When relative motion between two elements is completely or successfully constrained then these two elements form a

Answer is:

Kinematic pair

Explanation:

The two links or elements of a machine, when in contact with each other, are said to form a pair. If the relative motion between them is completely or successfully constrained (i.e. in a definite direction), the pair is known as kinematic pair.

When relative motion between two elements is completely or successfully constrained then these two elements form a

24) Ball bearing forms a

Answer is:

Rolling pair

25) Creep in Belt drive is due to

Answer is:

uneven extension and contractions of the belt when it passes from tight side to slack side

Explanation:

In Belt drives when the belt passes from the slack side to the tight side a certain portion of the belt extends. Similarly when the belt passes from the tight side to slack side it contracts. Hence creep in belt drive is due to uneven extensions and contractions of the belt when it passes from tight side to slack side.
This phenomenon of alternative stretching and contraction of the belt results in relative motion between the belt and the pulley surface. This relative motion is called creep.