Correct Answer : Platinum cobalt scale
Explanation : Colour is caused by the presence of colloidal substance is aquatic growth etc. in water should be distinguished from turbidity which is termed as apparent colour. The colour is expressed in Platinum Cobalt scale. Colour may be removed by coagulation and adsorption method.
Correct Answer : Option (B) : Outlets
Explanation : An outlet is a simple and small irrigation structure which is constructed along the distributaries. The amount of water that is withdrawn through the outlet is in proportion to the area that is irrigated below respective point.
Correct Answer : Option (A) : 2.5:1
Explanation : According to Terazghi, the following upstream slopes should be recommended.1. Homogeneous well graded – 2.5 : 12. Homogeneous coarse silt – 3 : 13. Sand and gravel with RCC core wall – 2.5 : 1.
Correct Answer : Option (A) : 0.25 to 5 cumecs
Explanation : The major distributary takes off from a branch canal to distribute the water to various parts of the field. The supply of the water varies from 0.25 to 5 cumecs.