127.  Most commonly used pump for lifting water in water supply mains, is
A. mdalflow pump
B. reciprocating pump
C. rotary type pump
D. centrifugal pumps

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128.  Pick up the correct statement from the following regarding radial flow centrifugal pumps :
A. These are provided with volute type or turbine type casings
B. In involute type of radial flow centrifugal -pump, the impeller discharges into a gradually expanding spiral casing
C. In turbine type of radial flow centrifugal pumps, the impeller is surrounded by stationary guide vanes to reduce the velocity of water
D. All the above.

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129.  In centrifugal pump installation,
A. pump is properly primed before starting
B. the diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe
C. the foot valve fitted at the bottom end of the suction pipe, prevents the movement of water from the pump when it is stopped
D. all the above. _

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130.  Pick up the correct statement from the following :
A. At a particular speed of operation, the head produced decreases with the increase of discharge
B. At zero discharge, discharge_ valve remaining closed, the head developed is maximum which is known as shut-off head
C. At a particular speed the discharge at which efficiency of a pump is maximum, is known as normal discharge
D. all the above.

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131.  For centrifugal pumps
A. initial cost is low
B. limited space is required
C. the discharge obtained is steady and non- pulsating
D. all the above.

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132.  The main draw-back of centrifugal pump, is
A. necessity of priming
B. discharge from pump varies with the load of water
C. for high heads, efficiency is low up to 50%
D. all the above.

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133.  Reciprocating pumps
A. are not suitable for variable heads
B. are four times costlier than centrifugal pumps
C. are not suitable for pumping water containing sediments
D. single stroke produce pulsating flow

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