Question

If (L) is the total head at inlet and (1) is the head loss due to friction, efficiency of power transmission  through a straight pipe is given by
1. \(\frac{{L - 1}}{L}\)
2. \(\frac{{L - 1}}{{L + 1}}\)
3. \(\frac{L}{{L + 1}}\)
4. \(\frac{L}{{L - 1}}\)

Answer 1

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 = \(\frac{{L - 1}}{L}\)