Question

Statement (I): In a reciprocating pump, the piston is considered to be moving with simple harmonic motion on the assumption that the connecting rod is very large compared to the crank length.

Statement (II): There is acceleration at the beginning and retardation at the end of each stroke.
1. Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)
2. Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)
3. Statement (I) is true but Statement (II) is false
4. Statement (I) is false but Statement (II) is true

Answer 1

Correct Answer - Option 2 : Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

A reciprocation pumps consists of a plunger or a piston that moves forward and backward i.e. harmonic motion inside a cylinder with the help of a large connecting rod and a crank. The crank is rotated by an external source of power.

Working of Reciprocating Pump:

Acceleration:

When the piston moves from the left to the right, a suction pressure is produced in the cylinder. If the pump is started for the first time or after a long period, air from the suction pipe is sucked during the suction stroke, while the delivery valve is closed. Liquid rises into the suction pipe by a small height due to atmospheric pressure on the sump liquid.

Retardation:

During the delivery stroke, air in the cylinder is pushed out into the delivery pipe by the thrust of the piston, while the suction valve is closed. When all the air from the suction pipe has been exhausted, the liquid from the sump is able to rise and enter the cylinder.