Electric current and circuits

As we know electricity is one of the important forms of energy. In the previous class we learnt about various aspects of electricity such as its sources materials which allow to pass it through the I.c conditiond and those who do not allow to pass it through them insulators some devices based on it its significance in modern life and also the dangers and harms association with it and precautions while using it. Let us know more about the electricity. 

The flow of electricity energy or electricity is called electric current .the ele8current passaes through conducting material which is generally in the form of wites. However on commercial scale electric current is supplied through cables to out houes offices shops factories etc electricity is used for various purposes such as lighting heating driving electricity  

Water is renewable natural resourc. It is vital body fluidics  which regulates life processes such as digestion of food transportation of nutrients and excretion of body wastes etc. It is also required for the germination of seeds. Water is an important participant of photosynthesis.  Water provides  habitat

To many animals and plants.  All animals and plants living in water are adapted to live in water.  There is enough fresh water on the earth to meet our present requirements. But there is a global shortage of usable water.  At Many places there is an acute shortage of water.  It is estimated that a few years from now more than one third of the people on our earth will not get sufficient water to live. The water table is falling in most areas. It something is not done to check it soon we will be facing water crisis. To prevent it we should have water.  As a part of community efforts in this direction water harvesting is being encouraged. 

                             HOW MUCH WATER ISAVAILABLE?

About 71 per cent of earth surface is covered with water. 

About 97.4 per cent cent of the total water on the earth is in ocean and Sean's. The water in oceans and seas cannot be used for drinking domestic use irrigation and industrial use because it contains many sales.

You already know that blowing air is called wind .wind is very useful for us wind power is used for pumping water for irrigation generating electricity moving blades of windmills etc. But when the wind blows too hard it causes a lot of destination.

Strong winds may uproot trees destroy electricity and telephone lines. 

               How is wind caused?

Wind is caused due to uneven heating of earth surface.

                                     The Beggar

kind sir have piry turn your attention to a poor hungry man for three days I have had nothing to eat I haven t five copecks for a lodging I swear it before god . for eight years I was a village sohoolteac .

intrigues. i fell a victim to calumny it is a year now since i have had anything to do the advocate sergei looked at the ragged fawn colored overcoat of the suppliant as his had seen  this aman somewhere before, I have not had an offer of a position in the province of kaluga the mendicant went on butI am obliged to by  circumstances . sergei eyes fell on the man overshoes one of bwhich was high and the other low and he suddenly remembered something ;

                  The Snake and Mirror

Has a snake ever coiled itself round any part of your body , A full blooded cobra all of us fell sell silent . the question came from the homeopath . the topic came up when we were discussing snakes. we listened attentiviy as the doctor continued with his tale ti was a hot summer night about ten clock i had my meal at the restaurant and  retuned to my room.

I heard a noise from above as I opened the door. The sound was a familiar one . One could say that the rats and i shared the rood I took out my box of matches and lighted the kerosene and the table. I took off my black coat white shirt and not sowhite vest and hung them up I opened the two windows in the room. it was an outer room with one facing the open yard. it had a tiled roof with long supporting gables that rested on the beam oves the wall. there was no ceiling there was a regular traffic of rats to and from the beam I mabe my bed verands for a little air but the wind god seemed to have taken time off. I went back into the room and sat down on the chair. I opened the box beneath the table and took out a book the materia medica . I opened it at the table on which stood the lamp and a large mirror a small comd lay besibe the mirror .One feels tempted to look into a mirror when it is near one. I took a look. In those bays i was a great admirer of beauty and I believed in making myself look handsome. I was unmarried and I was a doctor I felt i had to make my prsence felf i picked up the comd and ran it through my hair and adjusted the parting so that it looked straight and seera.

By now you have learnt that a number of important life processes continuosly take place within the body of is a living organism it is because of these life processes that organisms remainalive. The activities which keep an organism alive are nutrion growth respiration transportation and irritating etc you have already leam about nutrition let us read about respirator transportation of substances and excretion.

                        Why do we. Respire?

Our body needs energy for its various as activites.

This energy is produced in our body from the food we take the food we take has so stored chemical energy in it this energy is released when food is digested and the components of the digested food react with oxygen in the cell this process is called respiration. Therefore we respire to produce energy needed by the body for its various activities. To get oxygen we need to :

Breathe fresh air rich in oxygen. 

Transport the inhaled oxygen from respiratory organs to every call in the body.

you already know that blowing air biowing air is called wind. wind is very useful for us wind power is uned for pumping water for irrigation generating electricty moving blades of windmills etc . but when the wind blowe too hard it causes a lot of destruction . strong winds may uproot trees destroy electricity and telephine lines ;

                                         Soil

soil is one of the most important natural resources. it is a mixture of different types of rock particles and remans of dead plants and animals soil is found all around us in gardens school playgound at the parks at construction sites around us in gardens school playground at the parks at construction sites and also in the fields. it lies beneath our feet and is often hidden by roads and buildings. prodably this is the reason we often fail to realize how much soil affects our lives.

                                                     uses of soil 

soil plays an important role in the survival of organisms on the earth. its uses are as  follows.

  soil is also very important as a habitat-a home for millions of soil organisms like insects. earthworms  bacteria fungi ect .

it provides anchorage to trees and vegetation. 

look around what do you see.

Many things a row of houses large trees small plants peopls birds animals and many othres.

Each house in your locality and alos elsewhere remains at its allotted plact the tree in near yous house remains there itself. birds keep flying from one place to another . they may sit for a while on a tree top people may sit or move from one place to another so we see there are two different types of odjects these are.

     .      the odjects which do not change thir position with time.

     .      the odjects which do not change their position with time are said to be at rest.

the objects which change their positions with time.

We use different kinds of substances in our homes every day . These substances include milk vinegar lime juice curd pure water baking soda salt sugar stain cleaner oven cleaner etc. All of these substance can be classified into acidic basic and neutral substances on the basis of their properties. 

                                     Acids

The word acid is derived from the latin word acidus meaning sour to taste. Acids are present in a number of food items life curd lemons raw mangoes tomatoes grapes apples tamarinds and vinegar.  Substances the contain acids are called acidic substances.