Question

A centrifugal pump with peripheral speed ‘V’ was selected for a total lift of 100 m. Actually pump was to be operated for a total lift of 400 m. the peripheral speed should actually be (other conditions remaining same)
1. 2 V
2. 4 V
3. 8 V
4. 1 V

Answer 1

Correct Answer - Option 1 : 2 V

V₁ = V  H₁ = 100 m

V₂= ?   H₂ = 400 m

\(\frac{{{H_1}}}{{N_1^2}} = \frac{{{H_2}}}{{N_2^2}}\)

N ∝ V

\(\frac{{100}}{{{V^2}}} = \frac{{400}}{{V_2^2}}\)

V₂ = 2 V