Science Olympiad Test: Sources of Energy-1 - Class 10 MCQ

Nuclear Energy is discharged by nuclear reactions either by fission or fusion. In nuclear fusion, atoms combine to form a larger atom. In nuclear fission, the division of atoms takes place to form smaller atoms by releasing energy. Nuclear power plants produce energy using nuclear fission. The energy produced in a nuclear reaction is tremendous and can be carried out in the absence of sunlight.

Silviculture is a major programme started to replenish depleting forests by growing more trees and plants.

In solar cookers, we use concave mirrors.
The reason behind using this mirror:

• Concave mirrors reflect light falling on it to a single focal point.
• So the concave mirror used in solar cookers absorbs all the incident sunlight and reflects it to a single focal point.
• The radiation at the focal point is very powerful as it contains a lot of concentrated thermal energy.
• Now when we place a cooking pot on the focal point where the light is concentrated the energy is powerful enough to cook food.
• Other mirrors like convex mirrors and plane mirrors can not be used in solar cookers as they do not have a focal point, so we can not concentrate the energy.

We started to explore the potential of solar energy only in the recent past. Power resources that are considerably new in terms of usage and are renewable are called non-conventional power resources. Petroleum, coal, and natural gas are conventional sources because they are being used for major power generation for a long time.

• Denmark is called the 'Country of Winds' as it has the highest proportion of wind power in the world.
• It has the highest proportion of wind power in the world.
• Wind dominated, with 47% of the green energy coming from wind turbines.
• Denmark fulfill 50% of its power requirements from renewable energy.

Anaerobic bacteria fermented the biodegradable material such as biomass, manure, sewage, municipal waste, plant waste in the absence of oxygen to produce biogas.

Yes, if we plant trees in a planned manner to ensure a continuous supply of wood.
Wood is a renewable source of energy. It is obtained by cutting trees. A new plant sapling usually takes more than 15 years to grow and mature into a tree. Therefore, replenishment of cut-down trees takes a very long time. Cutting down of trees causes depletion of the forests leading to imbalance in nature.

• Decomposition of domestic wastes under natural processes is called biodegradable pollution.
• Domestic waste are first collected from the household and their dumped in the open ground. Then they are collected and dumped into the landfills.  
• The breakdown of biodegradable waste occurs resulting in the formation of small particles of carbon, nitrogen and oxygen release which are used as manure.  
• The small biological organisms which help in biodegradation are known as decomposers.  
• The decomposers get nutrition by the degradation of degradable waste. Biodegradable wastes include paper, vegetable peels etc.

Incomplete combustion of coal produces carbon monoxide which is a poisonous gas. Complete combustion of coal gives carbon dioxide as a product it causes rise in atmospheric temperature. Products after combustion of petrol are carbon monoxide, carbon dioxide, sulphur dioxide, nitrogen dioxide, nitric oxide, volatile organic compounds and hydrocarbons.

• Carbon dioxide is a green house gas which is responsible for global warming.
• Sulphur dioxide gas is a corrosive and suffocating gas.
• Nitrogen dioxide leads to diseases that are related to respiratory tract and infection.
• Nitric oxide leads to formation of smog and acid rain. Hydrocarbons lead to global warming.

The Bhopal disaster also referred to the Bhopal gas tragedy. It was a gas leak incident on the 3rd December 1984 at the Union Carbide India Limited pesticides plant in Bhopal. Methyl isocyanate (MIC) gas was released during the tragedy. It killed more than three thousand people immediately.