# Mechanical Engineering - Hydraulic Machines - Discussion

Discussion Forum : Hydraulic Machines - Section 1 (Q.No. 6)
6.
Discharge of a centrifugal pump is
directly proportional to diameter of its impeller
inversely proportional to diameter of its impeller
directly proportional to (diameter)2 of its impeller
inversely proportional to (diameter)2 of its impeller
Explanation:

Discharge of a centrifugal pump is directly proportional to (Diameter)^2 of its impeller.

Head of a centrifugal pump is directly proportional to (Diameter)^2 of its impeller.

Power Developed of a centrifugal pump is directly proportional to (Diameter)^4 of its impeller.

Discussion:
49 comments Page 1 of 5.

Prithvi singh said:   4 years ago
Q is directly proportional to D^3.
(4)

DebashisD said:   2 years ago
Discharge = Q * D * N.
(1)

Shaik Murtuza said:   3 years ago
Option A is the correct answer.
(1)

Biswajit Das said:   5 years ago
Option C is correct.
That Q= π D b Vf.
Anyhow Vf is related to V and V is related to u and u =π D N /60.
So, Q is directly proportional to D^2.
(1)

Utsav said:   5 years ago
No, the Discharge of a centrifugal pump is Directly proportional to Impeller diameter.

You can refer to below-given affinity laws.

Q1/Q2 = D1/D2.
H1/H2 = (D1/D2)^2,
P1/P2 = (D1/D2)^3.

Q Indicates Flow that is discharged,
P Indicates Power.
(1)

Deepak Rathva said:   6 years ago
Q= π x D x B x Vf.

Here, B also depends on D.
Vf depends on u means depends on DN,
So Q is directly proportional to D^3,
So all options are wrong.

Pabitra said:   6 years ago
It should be diameter cube.

Pabitra said:   6 years ago
Q= 3.14 d b v = d^3 n so the correct answer will be d^3.

Muhammad Waqas said:   6 years ago
Q=πDb(V_f).

Where D=Diameter of impeller at inlet,
b=width of impeller at inlet,and
V_f=Velocity of flow at inlet.

Q=πDb(V_f).
Q=πDb(πDN/60).

Hence
Q is directly proportional to square of the diameter.

Kartheek said:   6 years ago
dicharge Q = pav, a= πd^2/4 so q is directly praporional to squre of diameter.