# Mechanical Engineering - Hydraulic Machines - Discussion

Discussion Forum : Hydraulic Machines - Section 1 (Q.No. 6)

6.

Discharge of a centrifugal pump is

Answer: Option

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.
Sushil said:
1 decade ago

Discharge of centrifugal pump is given by Q = (pi)(D2)(B2)(Vf2).

As per above equation option (A) is correct.

As per above equation option (A) is correct.

RAHUL said:
1 decade ago

Discharge of centrifugal pump is Q = area* velocity of flow.

Q = (pi)(D1)(B1)(VF1) = (PI)(D2)(B2)(VF2).

Where B1 and B2 are width of impeller at inlet and outlet and B1 and B2 are diameter of impeller at inlet and outlet and VF1 and VF2 are velocity of flow at inlet and outlet.

Q = (pi)(D1)(B1)(VF1) = (PI)(D2)(B2)(VF2).

Where B1 and B2 are width of impeller at inlet and outlet and B1 and B2 are diameter of impeller at inlet and outlet and VF1 and VF2 are velocity of flow at inlet and outlet.

Afrasiyab said:
9 years ago

Directly proportional to square of diameter.

Radhika said:
9 years ago

Directly proportional to diameter of its impeller. A is the correct answer.

Harry said:
8 years ago

As per Affinity Laws:

Speed is constant,

Q1/Q2 = (D1/D2)^3.

So, the answer is Discharge is inversely proportional to the cube of the diameter.

Speed is constant,

Q1/Q2 = (D1/D2)^3.

So, the answer is Discharge is inversely proportional to the cube of the diameter.

Anurag Adhikary said:
8 years ago

Correct the answers, it should be option A.

Kartheek said:
8 years ago

Discharge in centrifugal pump (Q) = pi * D * b * v.

where D = dia of the impeller at the inlet,

b = width of the impeller at the inlet

v = velocity of flow at the inlet.

So, according to the formula, discharge is directly proportional to Diameter of the impeller.

where D = dia of the impeller at the inlet,

b = width of the impeller at the inlet

v = velocity of flow at the inlet.

So, according to the formula, discharge is directly proportional to Diameter of the impeller.

Faisal mumtaz said:
8 years ago

Directly proportional to diameter so, option A is correct.

Honey said:
8 years ago

I think, All the options are not satisfied. The correct answer will be directly proportional to the cube of the diameter of vanes.

Smith said:
8 years ago

The discharge flow rate of a centrifugal pump is directly proportional to diameter. Discharge head is directly proportional to the square of the diameter. And power is directly proportional to the cube of the diameter. You can understand all this with the help of affinity laws.

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