The equivalent diameter for fluid flow through a channel of constant non-circular cross section of area ‘A’ is given by (where, P = perimeter of the channel in contact with the fluid)?

Zinc is not used________?

Sea weeds are an important source of________?

With increases in carbonisation temperature________?

consecutive reaction, as shown in the bellow figure, is characterised by ________?

Sulphur content in lighter and heavier petroleum products is generally determined respectively by ________?