Surge wave in a rectangular channel is an example of i) steady flow ii) unsteady flow iii) uniform flow iv) non-uniform flow The correct answer is A. (i) and (iii) B. (ii) and (iii) C. (i) and (iv) D. (ii) and (iv)

The correct answer is A. (i) and (iii).

A surge wave is a type of unsteady flow that occurs in a rectangular channel. It is characterized by a sudden increase in the flow velocity and a corresponding decrease in the water depth. Surge waves can be caused by a variety of factors, including changes in the upstream water level, the opening or closing of a gate, or the passage of a boat.

Steady flow is a type of flow in which the velocity and depth of the water do not change with time. Uniform flow is a type of steady flow in which the velocity of the water is the same at all points in the channel. Non-uniform flow is a type of flow in which the velocity of the water is not the same at all points in the channel.

Surge waves are an example of unsteady flow because the velocity and depth of the water change with time. They are also an example of non-uniform flow because the velocity of the water is not the same at all points in the channel.