Which of the following is the weakest part in the railway track?

Which of the following roads (pavements) does not develop any corrugations?

The energy gradient line is ___ to drop in bed, in an open channel.

_____ number is the ratio between inertia and viscous forces.

Flow in circular pipes will be turbulent is Reynolds number is _____

The frictional resistance is __ to the surface area of contact.

For super critical flow, Fr _____ 1.

The Velocity at which flow changes from viscous to turbulent is called ______ velocity.