Consider the following statements regarding the volute casing of a centrifugal pump:
1. Loss of head due to change in velocity is eliminated.
2. Efficiency of the pump is increased.
3. Water from the periphery of the impeller is collected and transmitted to the delivery pipe at constant velocity.
Which of these statements are correct?
a) 1,2 and 3 b) 1 and 2
c) 2 and 3 d) 1 and 3