23.
Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs.

24.
Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs?

27.
Which of the following hardness tests uses the depth of penetration caused by the indentor as the parameter for arriving at the hardness value of a material ?

28.
The malleability of a material is the property by virtue of which it can be rolled or hammered into thin sheets. Which of the following materials has the maximum malleability ?

30.
The pH value is the measure of hydrogen ion concentration in a solution. The term pH stands for the __________ in the solution.