Class 10 Science - Chapter Our Environment NCERT Solutions | Which of the following groups contain on

What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?

Give any two ways in which biodegradable substances would affect the environment.

If all the waste we generate is biodegradable, will this have no impact on the environment?

Which of the following constitute a food-chain?

(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat

Why are some substances biodegradable and some non-biodegradable?

How can you help in reducing the problem of waste disposal? Give any two methods.

What is ozone and how does it affect any ecosystem?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What is the role of decomposers in the ecosystem?

What will happen if we kill all the organisms in one trophic level?

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

What are the functions performed by the testis in human beings?

Why don’t two magnetic field lines intersect each other?

The radius of curvature of a spherical mirror is 20 cm. What is its focal length?

How is the amount of urine produced regulated?

The human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This is due to

(a) presbyopia.
(b) accommodation.
(c) near-sightedness.
(d) far-sightedness.

Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.

How is the concentration of hydronium ions (H₃O⁺) affected when a solution of an acid is diluted?

What happens to the image distance in the eye when we increase the distance of an object from the eye?

Which metals do not corrode easily?

Name a mirror that can give an erect and enlarged image of an object.