Question

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 at the same time, by what amount the power of the motor should be increased?

• A. $n^2$ times
• B. $n^3$ times
• C. n times
• D. $n^{3/2}$ times

Answer 1

The correct option is B $n^3$ times

Let us consider the problem:

Let the power is $F.v$

$v$ has to be increased by $n$ opposing force is proportional to $v^2$.

Totally, $n^3$.