Class 9 Science - Chapter Improvement in Food Resources NCERT Solutions | How do storage grain losses occur?

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?

Write an expression for the work done when a force is acting on an object in the direction of its displacement.

(a) Tabulate the differences in the characterisitcs of states of matter.
(b) Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy and density.

A driver of a car travelling at 52 km h^-1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h^-1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?

Give three examples of the range of variations that you see in life-forms around you.

Classify each of the following as a homogeneous or heterogeneous mixture.

soda water, wood, air, soil, vinegar, filtered tea.

What type of clothes should we wear in summer?

Find the energy in kW h consumed in 10 hours by four devices of power 500 W each.

We know that many human activities lead to increasing levels of pollution of the air, water-bodies and soil. Do you think that isolating these activities to specific and limited areas would help in reducing pollution?

An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes ¹⁶₈ X and ¹⁸₈ X in the sample?