___________and __________of radial flow reaction turbine are always full of water.

A)
Casing and penstocks
B)
Runner and penstocks
C)
Runner and draft tube
D)
Casing and runner

Correct Answer : Option (D) :   Casing and runner


Explanation : Casing and runner are completely covered by water as it is a reaction turbine in which pressure energy is predominant.