Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertilizer.
(c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.
(c) Farmers using good quality seeds, adopting irrigation, using fertilizers, and using crop protection measures for more production and best crop protection. These conditions help in large crop production at the same time.
How do you differentiate between capture fishing, mariculture and aquaculture?
How do good animal husbandry practices benefit farmers?
Explain any one method of crop production which ensures high yield.
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?
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?
Differentiate between striated, unstriated and cardiac muscles on the basis of their structure and site/location in the body.
Using a horizontal force of 200 N, we intend to move a wooden cabinet across a floor at a constant velocity. What is the friction force that will be exerted on the cabinet?
Write the chemical formulae of the following.
(a) Magnesium chloride
(b) Calcium oxide
(c) Copper nitrate
(d) Aluminium chloride
(e) Calcium carbonate.
How is soil formed?
Name the tissue responsible for movement in our body.
Give three features of cardiac muscles.
What are the limitations of Rutherford’s model of the atom?
Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.
Explain with examples (i) Atomic number, (ii) Mass number, (iii) Isotopes and iv) Isobars. Give any two uses of isotopes.
What is the quantity which is measured by the area occupied below the velocity-time graph?