Class 9 Science - Chapter Improvement in Food Resources NCERT Solutions | What are the advantages of inter-croppin

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?

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.

What is meant by a pure substance?

Which of the following materials fall in the category of a “pure substance”?

(a) Ice
(b) Milk
(c) Iron
(d) Hydrochloric acid
(e) Calcium oxide
(f) Mercury
(g) Brick
(h) Wood
(i) Air.

When a carpet is beaten with a stick, dust comes out of it. Explain.

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?

A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the source of the sound. What is the time interval between successive compressions from the source?

Complete the table:

Conduct a survey in your neighbourhood to find out what the three most common diseases are. Suggest three steps that could be taken by your local authorities to bring down the incidence of these diseases.

Convert into mole.

(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.

Diagrammatically show the difference between the three types of muscle fibres.