Question
Question: A pump motor is used to deliver water at a certain rate from a given pipe. To obtain 'n' times water...
A pump motor is used to deliver water at a certain rate from a given pipe. To obtain 'n' times water from the same pipe in the same time the amount by which the power of the motor should be increased –
A
n1/2
B
n2
C
n3
D
n
Answer
n3
Explanation
Solution
Volume delivered per sec. = Av
mass delivered per sec = Avd
momentum delivered per sec = Av2d = force
power = force × velocity= Av3d
i.e. power µ v3