18. The pump coverts energy (external driving source) into kinetic energy in the fluid by giving impulses to the fluid by impellers. A diffuser or volute converts most of the kinetic energy into pressure, i.e. these machines use the basic law (Bernoulli’s) of converting potential energy into kinetic energy. What pumps are above description? (A) Rotary pumps (B) Displacement pumps (C) Gear pumps (D) Centrifugal pumps