Correct Answer - Option 1 :
\(\frac{{L - 1}}{L}\)
Explanation:
The efficiency of power transmission:
L= Total head at the inlet
1= Head loss due to friction
Head available at the outlet of the pipe = Head at the inlet - Head loss due to friction
Head available at the outlet of the pipe = L - 1
The efficiency of power transmission = Head available at the outlet / Head at the inlet
The efficiency of power transmission = \(\frac{{L - 1}}{L}\)