Hydrosphere MCQ (Multiple Choice Questions) PDF - 130

MCQ 646: What makes sea water not to be safe for drinking ?

1. High salt concentration
2. High minerals
3. Marine water pollution
4. Density of saewater

MCQ 647: What is an approximate percentage of dissolved solid in seawater?

1. 0.045
2. 0.035
3. 0.045
4. 0.025

MCQ 648: Which three elements constitute 90% of the sea water?

1. Cl, Na, Mg
2. S, Ca, K
3. Cl, S, Si
4. C, K, O

MCQ 649: The secondary treatment reduces the BOD, ranges from

1. 20-50%
2. 40-70%
3. 70-80%
4. 70-95%

MCQ 650: 50% of the incident energy is lost due to:

1. Consumers
2. Producers
3. Microorganisms
4. Planktons