A motor of power `P_0` is used to deliver water at a certain rate through a given horizontal pipe. To increase the rate of flow of water through the same pipe n times, the power of the moter is increased to `P_1` to `P_0` is

Options

A. n:1
B. `n^2:1`
C. `n^3:1`
D. `n^4:1`

Explanation

Let,
`A^rarr =a_x hati+a_y hatj+a_k hatk`
`Brarr = hati+hatj`
The component of vector rarrA along the direction of
`rarrB =(barA.barB)/(|barB|`
`=((a_x hati+a_y hatj+a_2 hatk).(hati-hatj))/(sqrt(1^2+(-1)^2`
`=(a_x-a_y)/sqrt2`