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Q. 6.     Do you think it is better to use compost instead of chemical fertilisers? Why?

The use of compost is better than the use of chemical fertilizers because- (i) Compost is environment friendly to use. (ii) Compost is cheap to produce and easy and harmless to use. (iii) Compositing helps with the recycling of waste matter. (iv) Composting provides a way to dispose of grabage.

Q. 5.      (c) Write a story on how packaging increases the amount of garbage

Packaging increases the amount of garbage as we keep on throwing the packaging materials at improper places. Also, most of the packaging materials are plastic based which are non-recyclable and cannot be properly degraded. These wastes get into drains and block them, creating poolution.

Q. 5.     (b) Give an example in which packaging could have been reduced?
          

The usage of plastic bags as packaging of food items can be reduced. Food in plastic bags might affect our healtha and moreover plastic bags are non-recyclable and may pollute the environment.

Q. 5.     (a) Collect different kinds of packaging material. What was the purpose for which each one was used?                                Discuss in groups.
           

The different kinds of packaging materials commonly used includes: (i) Paper bags for carrying small groceries, medicines (ii) Cloth or jute bags for carrying fruits, vegetables, or other groceries (iii) Plastic bags for carrying fruits, vegetables and other household items. (iv) Cardboard boxes for transportation of packed material.

Q.  4.     (b) With the help of a lens look at the pieces of paper you collected for the above question. Do you see any difference in the material of recycled paper and a new sheet of paper ?

It is very difficult  to find out the difference between a recycled paper and a new sheet of paper. Although recycled paper will seem rough.

Q. 2.     Discuss :

             (a) Is garbage disposal the responsibility only of the government?
  

No, garbage disposal is not only the responsibility of the government.It is the responsibility of the citizens as well. It is one's duty to keep the environment clean. The people should throw garbage at proper place. Moreover, we should start recycling waste.

Q. 1    (b) Have you seen any other organism besides redworms, in your pit? If yes, try to find out their names. Draw pictures of these.

Yes, a pit contains other organisms such as beetles, spiders and oter types of earthworm. Moreover it contains microscopic bacteria.

Q. 1.     (a) Which kind of garbage is not converted into compost by the redworms?
              

Non-biodegradable wastes are not converted into compost by the red worms. Example: Plastic bags, plastics, aluminium foil, etc. 

Q. 8.     When does a drought occur ?

When there is no rain for one or two years then chances of Drought occcurs. Because usually, due to evaporation and transpiration water is lost by soil , pods ,lakes etc. But if no rainfall will occurs for a longer periode of time, then water level in various ponds, river ,lakes and wells decreases. This leads to the condition of drought.    

Q. 7.     How are clouds formed?

We know that clouds are formed by the process of condensation and evaporation. When water from the oceans,ponds, rivers, lakes, plants, fields, and other land surfaces evaporates, warm and moist air rises in the atmosphere. At higher altitudes, when the air becomes cooler and water vapoure contained in air condenses. On condensation, these form tiny water droplets. These tiny water droplets...

Q. 6.     To clean their spectacles, people often breathe out on glasses to make them wet. Explain why the glasses become wet.

Because as the breath that is coming out of the mouth is moist , thereby making the glass of specacles cooler. And because of that,water vapours that are  present in the air surrounding the glass condense and get attached to the glass surface. Therefore, the glass becomes wet.  

Q. 5.     Take out a cooled bottle of water from refrigerator and keep it on a table. After some time you notice a droplets of water around it. Why?

This will happen because when we take a water bottle out of refrigerator, the surface of water bottle is cold which cools the surrounding air and because of condensation water vapoure in the air condenses around the surface of the bottle and form  droplets of water around it.  

Q.  4.     Suppose you want to dry your school uniform quickly. Would spreading it near an anghiti or heater help? If yes, how?

Yes, i will spread it near an anghiti or heater, because heat generated from an angithi or a heater causes the water to evaporate at a faster rate. Therefore, helps in  drying the clothes quicker rate.  

Q. 3.     Which of the following statements are “true” ?

            (a) Water vapour is present in air only during the monsoon. ( )
            (b) Water evaporates into air from oceans, rivers and lakes but not from the soil.( )
            (c) The process of water changing into its vapour, is called evaporation.( )
            (d) The evaporation of water takes place only in sunlight.( )
            (e) Water vapour condenses to form tiny droplets of water in the upper layers of air where it is cooler.( )

(a) Water vapour is present in air only during the monsoon.  FALSE Correct :- There is always a small amount of water vapor present in air.         (b) Water evaporates into air from oceans, rivers and lakes but not from the soil.  FALSE Correct :- Water also evaporates from the soil. (c) The process of water changing into its vapour, is called evaporation. TRUE             (d) The...

Q. 2.     State for each of the following whether it is due to evaporation or condensation:

            (a) Water drops appear on the outer surface of a glass containing cold water.
            (b) Steam rising from wet clothes while they are ironed.
            (c) Fog appearing on a cold winter morning.
            (d) Blackboard dries up after wiping it.
            (e) Steam rising from a hot girdle when water is sprinkled on it.

(a) Water drops appear on the outer surface of a glass containing cold water.    Condensation (b) Steam rising from wet clothes while they are ironed.   Evaporation             (c) Fog appearing on a cold winter morning.    Condensation             (d) Blackboard dries up after wiping it.    Evaporation             (e) Steam rising from a hot girdle when water is sprinkled on it.    Evaporation

Q. 1.     Fill up the blanks in the following:

            (a) The process of changing of water into its vapour is called _________________.
            (b) The process of changing water vapour into water is called _________________.
            (c) No rainfall for a year or more may lead to _________________ in that region.
            (d) Excessive rains may cause _________________.

(a) The process of changing of water into its vapour is called  evaporation             (b) The process of changing water vapour into water is called  condensation (c) No rainfall for a year or more may lead to  drought   in that region. (d) Excessive rains may cause  floods.

Q2.    Mark 'True' or 'False' for following statements:
                (a) Electric current can flow through metals.
                (b) Instead of metal wires, a jute string can be used to make a circuit.
                (c) Electric current can pass through a sheet of thermo Col.

(a) True, electric current can flow through metals. (b) False, a jute string is not a conductor of electricity. (c) False, thermocol is not a conductor of electricity.  

Q10.    The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?

Plastic or rubber is a good insulator that does not allow the current to pass through it. Hence, the covering of plastic or rubber is made so that electric current may not pass through these tools to the body of the electrician to harm them.

Q9.    Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.

Electrician uses rubber gloves while reparing an electric switch because rubber is a insulator and during the work when current carrying wires comes in contact the body then there will not be any shock as the rubber does not allow the current to pass thorugh it.

Q8.    Using the "conduction tester" on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.

Yes, if the object is a good conductor of electricity then the current will flow through the tester and the bulb will glow. Hence, the object is a conductor of electricity.  
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