Q10
1 markMCQSection A

Which one of the following statements is not true about nuclear energy generation in a nuclear reactor?

(A) Energy is obtained by a process called nuclear fission.

(B) The nucleus of Uranium is bombarded with high energy neutrons.

(C) A chain reaction is set in the process.

(D) In this process a tremendous amount of energy is released at a controlled rate.

OR

The biggest source of energy on Earth's surface is

Our Environment
Food Chains and Webs

Options

(A)Biomass
(B)Solar radiations
(C)Tides
(D)Winds
Official Answer

The correct option is (B).


The biggest source of energy on Earth's surface is solar radiation (sunlight). Autotrophs (green plants) capture about 1%1\% of the energy of sunlight that falls on their leaves and convert it into food energy, which then flows through all other trophic levels in the ecosystem.

solar radiationssunlightprimary source of energyautotrophs

Marking Scheme

  • 11 mark for selecting the correct option (B)

Hint

Think about which source of energy is captured by green plants to initiate the flow of energy in any food chain.

Quick Oral Answer

The ultimate source of energy for all ecosystems on Earth is the Sun, as green plants use solar radiation to synthesize food.

Analysis & Explanation

The Sun is the primary and ultimate source of energy for almost all life forms on Earth.

  • Option (B) is correct because solar radiation provides the light and heat energy required for photosynthesis by producers, which forms the base of all food chains.
  • Option (A) Biomass is incorrect because biomass energy is stored solar energy in organic matter.
  • Option (C) Tides are driven by gravitational forces of the moon and sun, contributing very little to the overall energy budget of the Earth's surface.
  • Option (D) Winds are generated due to the uneven heating of the Earth's surface by solar radiation, making wind a secondary source derived from solar energy.

Common Mistakes

  1. 1Students might confuse biomass as the primary source because it is organic, but biomass itself is produced using solar energy.

Interesting Facts

Only about 1%1\% of the solar energy falling on the leaves of green plants is actually converted into chemical energy during photosynthesis, yet this small fraction sustains almost the entire biosphere!

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2020?

This question carries 1 mark in the CBSE Class 10 Science 2020 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Our Environment" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Food Chains and Webs" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2020 paper?

This is a MCQ question from Section A in the CBSE Class 10 Science 2020 paper.