# In a single-acting reciprocating pump, the acceleration head at the beginning of the suction stroke is 3.5 m. If the pump is 1.5 m below the water lev

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In a single-acting reciprocating pump, the acceleration head at the beginning of the suction stroke is 3.5 m. If the pump is 1.5 m below the water level in the supply reservoir, the pressure head at the cylinder at that instant, considering the atmospheric pressure as 10.0 m is
1. 2 m (abs)
2. 4 m (abs)
3. 8 m (abs)
4. 16 m (abs)

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Correct Answer - Option 3 : 8 m (abs)

In single-acting reciprocating pump , head available at cylinder (H) is given by

H= Hatm – Hsuction head – Hsuction acceleration – Hsuction friction loss

Hatm = 10 m (Given)

HSuction friction loss = Neglected as not given

HSuction head = 1.5 m (Given)

HSuction acceleration = + 3.5 (At beginning of stroke)

HSuction acceleration = - 3.5 (At the end of stroke)

HSuction acceleration = 0 (At mid-stroke)

Case 1:

At beginning of stroke:

H = 10 - 1.5 - 3.5 = 5 m

Case 2:

At end of stroke:

H = 10 - 1.5 - (-3.5) = 8 m

∴ Pressure head at cylinder, considering at the end of stroke is 8 m (absolute).