So, Answer (D) and Bed slope (S) to the power of 1/3 not 1/2.

Sudip said:
(Aug 4, 2017)

According to Lacey's formula,

Regime flow equation V= 10.80 R^2/3 S^1/2.

Majumder said:
(Nov 14, 2017)

I agree @SUDIP.

Ramavtar said:
(Jan 9, 2018)

Lacey's formula.

Regime flow equation V= 10.80 R^2/3 S^1/2.

Sanath said:
(Jan 11, 2018)

Correct answer is d.

Mahe said:
(Feb 17, 2018)

None of the option is true because according to the formula the powers are 2/3 & 1/3 for R & S respectively.

Chandu said:
(Mar 23, 2018)

The Answer is D.

Sam said:
(Apr 24, 2018)

D is the correct option.

Ganesh said:
(Jul 18, 2018)

Here, V=10.8 R^2/3 S^1/3.

Chinmoy said:
(Jul 19, 2018)

You are absolutely right @Mahe.

All other answer is based on Manning's formula.

Musab said:
(Aug 17, 2018)

The correct answer is R^3/4 S^1/2.
R^2/3 S^1/2 is Mannings equation.
And other equation by Lacey is 16 R^2/3 S^1/3 used for calculating the flood discharges in rivers.