Two Marks Questions with Answers

Two Marks Questions with Answers

Q.1 What is renewable energy ?

Ans. : Renewable energy :

• Renewable energy, often referred to as clean energy, comes from natural sources or processes that are constantly replenished.

• For example, sunlight or wind keep shining and blowing, even if their availability depends on time and weather.

• While renewable energy is often thought of as a new technology, harnessing nature’s power has long been used for heating, transportation, lighting and more.

Q.2 Why water is a unique natural resource ?

Ans. : Water is unique natural resource :

• Water is an important component of all the living beings. Water is used for drinking, cleaning, agriculture, power generation, industrial purpose.

• Only 1 % of water is readily available for human kind hence it is a unique natural resource.

Q.3 What are fossil fuels and why they are non-renewable ?

Ans. : Fossil Fuels :

• Fossil fuels are hydrocarbon-containing materials of biological origin occurring within Earth’s crust that can be used as a source of energy.

• Coal, oil and natural gas are called as fossil fuels.

• The energy can be obtained by burning or lightening them. Once they burnt they can not be regenerated hence they are called as non-renewable.

Q.4 What are the environmental benefits of solar energy?

Ans.: Environmental Benefits of Solar energy :

• Solar power, like other renewable energy resources, has many environmental and health benefits.

• Solar reduces greenhouse gas emissions, which contribute to climate change and also results in fewer air pollutants like sulphur dioxide and particulate matter, which can cause health problems.

Q.5 How do solar photovoltaic (PV) panels work?

Ans.: PV Panel:

• Solar panels absorb the sun's energy throughout the day and convert it into Direct Current (DC) electricity. 

• Most homes and businesses run on Alternating Current (AC) electricity, so the DC electricity is then passed through an inverter to convert it to usable AC electricity. At that point, you either use the electricity in your house or send it back to the electric grid.

Q.6 Differentiate between renewable and non-renewable natural resources.

AU : May-08, 19

Ans. :

Renewable

These are the sources which regenerates the natural processes with a reasonable time period.         

Non-renewable

These sources are not capable to regenerate.

Q.7 What are the conventional sources of energy for the man kind ?   

AU : Dec.-05

Ans. : Non-renewable energy sources are the conventional sources of energy. These resources can not be generated after they exhausted.

Example : Oil, gas, coal etc.

Q.8 Define sustainable forestry.

Ans. : It is the highest rate at which the forest resources can be used without reducing its supply to future generation.

Q.9 State the environment effects of extracting and using mineral resources.

AU : May-08

OR Mention any two environmental effects of mining for mineral resources.

AU : May-16

Ans. :

1. Surface and ground water pollution

2. Soil erosion

3. Air pollution

4. Adverse effect on biomass, ecosystem

5. Devegetation of land

Q.10 Define water logging.

Ans. : Water logging is the state of land with excess of water.

Q.11 Define soil erosion.

Ans.: Soil erosion is a process of degradation of topsoil of land.

Q.12 What are renewable resources ?

Ans. : The resources that regenerates through natural processes with reasonable time period is called renewable resources. 

Q.13 What do you mean natural resources ? Give examples.      

AU : May-14      

Ans. : Natural resources : The variety of things processes obtained from environment to satisfy human needs and wants are called as natural resources.

Example : air, water forest minerals etc.

Q.14 What are the energy needs procured for India ?        

AU : May-14      

Ans.: Energy procurement from different sectors in India :

i) Thermal power - 30 % approx      ii) Hydro power - 20 % approx

iii) Nuclear power - 1 % approx                

Q.15 Write the problems due to construction.  

AU : May-14      

Ans.: Problems due to construction :

1. Environmental degradation

2. Deforestation (Loss of agriculture land)

3. Increase in green house effect.      

4. Reduction in ground water level. 

Q.16 Define non-renewable resources.    

Ans. : Non-renewable resources : Non-renewable energy resources are those natural resources which are finite and exhaustible.

Example : Coal, pertroleum, natural gas etc.

Q.17 What is desertification ?         AU : May-15      

Ans. : Desertification is a form of land degradation. Occuring is semi-arid areas due to anthropogenic activities.

Q.18 What do you mean by land degradation ?        AU : Dec-15        

Ans. : Land Degradation : Any change in land that reduces its quality and productivity is referred as land degradation. The land degradation results in deterioration of soil or loss of fertility of the soil.

Q.19 What are the causes of land degradation ?       

AU : May-16      

Ans.:

1. Population      

2. Urbanization

3. Fertilizers and pesticides    

4. Damage to top soil

5. Waterlogging   

Q.20 What is Biogas ? Mention its uses.  

AU : Dec.-16       

Ans. : Biogas is a mixture consisting of 65 % methane (CH4) and of 35 % CO2. It is renewable energy resulting from biomass.

Uses of Biogas : 1. Cooking fuel 2. Heating fuel 3. Production of electricity       a

Q.21 Write any two problems caused by high saline soils.

Ans.:

1. Because of salinity the soil becomes alkaline and crop yield decreases severely.

2. Salinization of land leads to stunt growth.

3. The land becomes impotent and no crop can be cultivated.

Q.22 Define producers

Ans. : The producers use energy from the sun and nutrients like nitrogen and phosphorous from the soil to produce high energy compounds.

For example - Green plants, trees.

Q.23 Name the four ecosystems.

Ans.:

1. Forest ecosystem.     

2. Grassland ecosystem.

3. Desert ecosystem.

 4. Aquatic ecosystem.

Q.24 Define Ecosystem.

Ans.: Ecosystem

• An ecosystem includes all of the living things (plants, animals and organisms) in a given area, interacting with each other, and also with their non-living environments (weather, earth, sun, soil, climate, atmosphere).

• Ecosystems are the foundations of the Biosphere and they determine the health of the entire earth system.

• The living things are biotic features, and the non-living things are abiotic features.

• There are very many types of ecosystems out there, but the three major classes of ecosystems, (sometimes referred to as biomes), are the following :

1. Freshwater Ecosystems 2. Terrestrial Ecosystems 3. Ocean Ecosystems

• All ecosystems have three basic components:

1. Autotrophs (producers of energy) 2. Heterotrophs (consumers of energy)

3. Non-living matter