Explain any one method of crop production which ensures high yield.
One of the methods of crop production that ensures high yield is crop rotation. This method involves growing two or more varieties of crop in the same fertile land in a sequential and seasonal order in a definite pattern. A crop utilises some particular nutrients in larger quantities from the soil and thus the soil gets enriched in this process. Therefore, crops having different nutrient requirements are rotated. For example, legumes which have nitrogen-fixing bacteria in their root nodules supply the soil with nitrogen.
How do you differentiate between capture fishing, mariculture and aquaculture?
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?
How are fish obtained?
What is genetic manipulation? How is it useful in agricultural practices?
What are the desirable agronomic characteristics for crop improvements?
What factors may be responsible for losses of grains during storage?
Which method is commonly used for improving cattle breeds and why?
How do biotic and abiotic factors affect crop production?
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?
Define 1 watt of power.
What is the kinetic energy of an object?
Which wave property determines
(a) loudness, (b) pitch?
Gravitational force acts on all objects in proportion to their masses. Why then, a heavy object does not fall faster than a light object?
What is power?
What are the various energy transformations that occur when you are riding a bicycle?
When do we say that work is done?
How do substances like CO2 and water move in and out of the cell? Discuss.
Certain force acting on a 20 kg mass changes its velocity from 5 m s-1 to 2 m s-1. Calculate the work done by the force.
A bus starting from rest moves with a uniform acceleration of 0.1 m s-2 for 2 minutes. Find (a) the speed acquired, (b) the distance travelled.