What are the advantages of inter-cropping and crop rotation?
Inter-cropping and crop rotation both play an important role in increasing the yield of crops. Inter-cropping helps to maintain soil fertility and prevents pests and diseases from spreading throughout the field. It increases productivity per unit area. Crop rotation improves the soil fertility and avoids depletion of a particular nutrient. It minimizes the pest infestation and diseases. Both these methods reduce the need for fertilizers. It also helps in controlling weeds and controls the growth of pathogens and pests in crops.
How do you differentiate between capture fishing, mariculture and aquaculture?
Explain any one method of crop production which ensures high yield.
How do good animal husbandry practices benefit farmers?
What are the desirable characters of bee varieties suitable for honey production?
How do plants get nutrients?
What is genetic manipulation? How is it useful in agricultural practices?
How are fish obtained?
What are the desirable agronomic characteristics for crop improvements?
Which method is commonly used for improving cattle breeds and why?
What factors may be responsible for losses of grains during storage?
Which of the following has more inertia: (a) a rubber ball and a stone of the same size? (b) a bicycle and a train? (c) a five-rupees coin and a one-rupee coin?
State the universal law of gravitation.
Which of the following are matter?
Chair, air, love, smell, hate, almonds, thought, cold, cold-drink, smell of perfume.
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (Fig. 11.3). Let us take it that the force acts on the object through the displacement. What is the work done in this case?
What is meant by a pure substance?
How does the sound produced by a vibrating object in a medium reach your ear?
In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium observations are in agreement with the law of conservation of mass.
sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water
What are canal rays?
State any two conditions essential for good health.
How is our atmosphere different from the atmospheres on Venus and Mars?
What would happen if the plasma membrane ruptures or breaks down?
Abdul, while driving to school, computes the average speed for his trip to be 20 km h-1. On his return trip along the same route, there is less traffic and the average speed is 40 km h-1. What is the average speed for Abdul’s trip?
What is the major source of fresh water in the city/town/village where you live?
How are sol, solution and suspension different from each other?
Why is the weight of an object on the moon 1/6th its weight on the earth?
What are canal rays?
What is the nature of the distance-time graphs for uniform and non-uniform motion of an object?
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
State any two conditions essential for being free of disease.
In which of the following case do you think the long-term effects on your health are likely to be most unpleasant?
• if you get jaundice,
• if you get lice,
• if you get acne.
Why?