If H = total head at inlet, hf = head lost due to friction, Efficiency of power transmission through pipe is given by
1
\(\frac{{\left( {{\rm{H}}\,{\rm{ - }}\,{{\rm{h}}_{\rm{f}}}} \right)}}{{\rm{H}}}\)
2
\(\frac{{\rm{H}}}{{\left( {{\rm{H}}\,{\rm{ + }}\,{{\rm{h}}_{\rm{f}}}} \right)}}\)
3
\(\frac{{\left( {{\rm{H}}\,{\rm{ - }}\,{{\rm{h}}_{\rm{f}}}} \right)}}{{\left( {{\rm{H}}\,{\rm{ + }}\,{{\rm{h}}_{\rm{f}}}} \right)}}\)
4
None of these