Mention the advantages of solar cells. [3 MARKS]
Each point: 1 Mark Advantages of solar cells are as follows:
1) No moving parts.
2) Little maintenance is required.
3) Can be set up in remote places.
What is composite fish culture? Mention its two advantages. [3 MARKS]
Mention five advantages of polythene over natural materials. [5 MARKS]
Write a short note on ground water harvesting. Mention the advantages. [5 MARKS]