The volute casing of a centrifugal pump has which of the following functions?
1. Eliminating loss of head due to change in velocity after exit from impeller.
2. Directs the flow towards the delivery pipe
3. Converts a part of the velocity head to pressure head
4. Gives a constant velocity of flow
Select the correct answer using the code given below:
a. 1, 2 and 4 b. 2 and 3 only
c. 1 and 4 only d. 2 and 4 only