Correct Answer - Option 2 : 43.38 m

**Concept:**

Manometric Efficiency (ηman)

\({\eta _{man}} = \frac{{{H_m}}}{{\frac{{{V_{w2}}{u_2}}}{g}}} = \frac{{g{H_m}}}{{{V_{w2}}{u_2}}}\)

**Calculation:**

**Given:**

D_{2} = 30 cm, N_{2} = 1450 rpm, η_{man }= 82%, g = 9.81 m/s2

\(u_2=\frac{\pi D_2N_2}{60}\)

\(u_2=\frac{\pi \times 0.3\times 1450}{60}=22.765\;m/s\)

For radial outlet V_{w2} = u_{2}

\({\eta _{man}} = \frac{{g{H_m}}}{{{}{u_2}^2}}\)

\(0.82 = \frac{{9.81 \times {H_m}}}{{{}{22.765}^2}}\)

H_{m} = 43.32 m