G₁ and G₂ are the slopes of the approach and departure grades of a vertical curve, respectively.

Given |G₁| < |G₂| and |G₁| ≠ |G₂| ≠ 0

Statement 1 : +G₁ followed by +G₂ results in a sag vertical curve.

Statement 2 : −G₁ followed by −G₂ results in a sag vertical curve.

Statement 3 : +G₁ followed by −G₂ results in a crest vertical curve.

Which option amongst the following is true?

A very wide rectangular channel carries a discharge (Q) of 70 m³/s per meter width. Its bed slope changes from 0.0001 to 0.0009 at a point P, as shown in the figure (not to scale). The Manning’s roughness coefficient of the channel is 0.01. What water surface profile(s) exist(s) near the point P?

A jet of water having a velocity of 20 m/s strikes a series of plates fixed radially on a wheel revolving in the same direction as the jet at 15 m/s. What is the percentage efficiency of the plates? (round off to one decimal place)