The most suitable chemical which can be applied to the water surface for reducing evaporation is

Finally formed berms in canals are provided for

A. Protection of banks erosion by the waves

B. Control of seepage losses

C. Strengthening of banks

D. All the above

Canals constructed for draining off water from water logged areas, are known

A. Drains

B. Inundation canals

C. Valley canals

D. Contour canals

A hydroelectric scheme operating under a head of 80 m will be classified as

A. low head scheme

B. medium head scheme

C. high head scheme

D. none of the above

Irrigation water having the concentration of Na⁺⁺, Ca⁺⁺ and Mg⁺⁺ as 20, 3 and 1 Milli equivalent per litre respectively will be classified as

A. Low sodium water

B. Medium sodium water

C. High sodium water

D. Very high sodium water