# Civil Engineering - GATE Exam Questions - Discussion

### Discussion :: GATE Exam Questions - Section 3 (Q.No.16)

16.

Water flows at a depth of 0.1 m with a velocity of 6 m/s in a rectangular channel. The alternate dpeth is

 [A]. 0.30 m [B]. 0.40 m [C]. 0.86 m [D]. 0.81 m

Explanation:

No answer description available for this question.

 Shaheen said: (Feb 6, 2015) y2/y1 = 1/2[-1+sqrt(1+8Fr2)].

 Hamza said: (Apr 3, 2018) The answer is "A" because on equating the equations E=Y+ (V)2/2g as a first equation and E=Y+(q/y)2/2g we get nearly .32.

 Neeraj Nautiyal said: (Apr 5, 2018) Can anyone please explain this?

 Basith said: (Oct 2, 2018) 0.1/2*(√(1+8*Fr^2)-1) = 0.808. fr = 6/√(9.81*0.1).

 Keshav Kaushik said: (Jan 6, 2019) Fr = V/√(gL) = 6. y2 = y1* 0.5* [ -1+ √( 1+8*Fr^2)]. y2 = 0.8 is the answer.

 Anomiee said: (Jan 11, 2019) Here it is asking about alternate depth not sequent depth. For alternate depths, we have to equate specific energies at the two sections.

 Replyfast said: (Dec 15, 2019) Can anyone explain how to calculate alternate depth for this numerical problem?

 Mayuri Jamdade said: (Oct 30, 2020) Y2 = 1/2 * Y1 * (((1+(8 * Fr^2))^0.5)-1). Fr = (V/((gY1)^0.5)) = (6/((9.81*0.1)^0.5)) = 6.06 Y2 = 0.5 * 0.1*(((1+(8 * 6.06 * 6.06))^0.5)-1) = 0.808m Y2 = 0.808m is approximately 0.81m.