Question

1. In a uniform open channel flow:
   1. The total energy remains constant along the channel
   2. The total energy line either rises or falls along the channel depending on the state of the flow
   3. The specific energy decreases along the channel
   4. The line representing the total energy is parallel to the bed of the channel

2. In which of the following situations, the flow is uniform?
   1. Flow in channel contraction or expansion
   2. Flow in the vicinity of a bridge pier
   3. Flow at the middle of a long prismatic channel far away from the obstruction

3. Uniform flow in an open channel exists when the flow is steady, and the channel is
   1. Prismatic
   2. Non-prismatic and the depth of the flow is constant along the channel
   3. Prismatic and the depth of the flow is constant along the channel
   4. Frictionless

4. In uniform flow, there is a balance between:
   1. Gravity and frictional forces
   2. Gravity and inertial forces
   3. Inertial and frictional forces
   4. Inertial and viscous forces

5. The water depth in a wide channel is equal to 1.2m (For a very wide channel R is approximately equal to y). If the Chezy coefficient is equal to 49 (metric), then Manning coefficient n (metric) is equal to:
   1. 0.024
   2. 0.021
   3. 0.026

Answer 1

IN UNIFORM CHANNEL

TOTAL ENERGY = Y + Z + V2/(2*g) ..... FOR A UNIFORM OPEN CHANNEL DEPTH IS CONSTANT ALONG WITH VELOCITY HEAD AND HENCE TOTAL ENERGY TOTALLY DPENDS ON Z WHICH IS NOTHING BUT BED ELEVATION FROM CHOOSEN DATUM HENCE ''d" OPTION IS MOST APPROPRIATE.

FLOW WILL BE UNIFORM ONLY IF IT IS FREE FROM OBSTRUCTION AND CHANNEL IS PRISMATIC. HENCE c OPTION IS CORRECT. a AND b OPTION SHOWS OBSTRUCTED FLOW.

UNIFORM FLOW EXIST ONLY IF CHANNEL IS PRISMATIC AND DEPTH OF FLOW IS CONSTANT( INFACT UNIFORM FLOW GETS ITS NAME FROM THIS I.E. DEPTH UNIFORM). HENCE C OPTION IS MOST APPROPRIATE.

UNIFORM FLOW OCCURS IF GAIN ENERGY DUE TO ELEVATION (I.E. GRAVITY ENERGY) IS EQUAL TO LOSS IN ENERGY DUE TO FRICTION. HENCE A OPTION IS CORRECT.

USING HERE R=(AREA/ PERIMETER) FOR WIDE CHANNEL R= WATER DEPTH = 1.2m. IN THIS CASE. C=49 PUTTING IN EQUATION WE GET n=0.021 I.E. B OPTION

FEEL FREE TO REACH OUT TO ME THROUGH COMMENT SECTION IF ANY DOUBT COMES, AND IF YOU LIKE MY WORK THEN PLEASE DO THUMBS UP