Class 9 Science - Chapter Improvement in Food Resources NCERT Solutions | What are the desirable characters of bee

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?

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?

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?

A hammer of mass 500 g, moving at 50 m s^-1, strikes a nail. The nail stops the hammer in a very short time of 0.01 s. What is the force of the nail on the hammer?

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

Calculate the number of molecules of sulphur (S8) present in 16 g of solid sulphur.

What is the audible range of the average human ear?

A submarine emits a sonar pulse, which returns from an underwater cliff in 1.02 s. If the speed of sound in salt water is 1531 m/s, how far away is the cliff?

Why are we able to sip hot tea or milk faster from a saucer rather than a cup?

Does sound follow the same laws of reflection as light does? Explain.

What are the limitations of Rutherford’s model of the atom?

Differentiate between homogeneous and heterogeneous mixtures with examples.

If an atom contains one electron and one proton, will it carry any charge or not?