Correct Answer - Option 4 : at right angle to weir crest in both
Explanation:
Chute spillway:
(i) Spillway discharge flows in open channel from the reservoir to the downstream river.
(ii) Open channel can be loacted either along the abutment of the dam or through a saddle.
(iii) Generally provided on earth dam or rockfill dam.
(iv) The chutes is in general narrowed for economy and then widened near the end to decrease the discharge velocity.
(v) The flow of water after spilling over the weir crest in chute spillway respectively are at right angle to weir crest in both.
(vi) Chute spillway is generally used
- to control gully head;
- to convey the runoff from upstream areas into the gully, very smoothly without erosion;
- as a structure for flood prevention, water conservation and collection of sediments and
- for controlling the gradient of natural or artificial channels.