A steep wide rectangular channel takes off from a reservoir

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A steep wide rectangular channel takes off from a reservoir having an elevation of 101.2 m. At the entrance, the bottom elevation of the channel is 100 m. If the slope of the channel is increased by 4%, the discharge per unit length in the channel will be

1. 2.24 m² / s
2. higher than 2.24 m² / s by 4%
3. higher than 2.24 m² / s by 2%
4. choked

Correct Option: C

Q = AV
V ∝ √S
S₁ = S
S₂ = 1.04 S

= 1 + .02 = 1 + 2%
∴ % increase is 2%