Topic name

Sex ratio

Production of Electricity

DEFORSTATION

Sex Ratio

Sex Ratio—Proportion of males relative to females in a population

General formula:

SR = Number of males/Number of females*100

Sex Ratio:

Males population= Pm

Females Population=Pf

Total population=Pt

Pt=Pm +Pf

Sex Ratio of Births

Sex Ratio of Births

Sex Ratio of Births—Number of male births per 100 female births

=Number of male births/Number of female births*100

Ratio < 100 →More female than male births

= 100 → Same number of male and

female births

> 100 → More male than female births

Sex Ratio of Deaths

Sex Ratio of Deaths:

Sex Ratio of Deaths—Number of male Deaths per 100 female Deaths

=Number of male Deaths/Number of female Deaths*100

Ratio < 100 →More female than male Deaths

= 100 → Same number of male and

female Deaths

> 100 → More male than female Deaths

Sex Ratio of Migrants

Sex Ratio of migrants:

Sex Ratio of Migrants—Number of male Migrants per 100 female Migrants

=Number of male Migrants/Number of female Migrants*100

What is Electricity?

Electricity is the form of energy that can be easily changed to other form.

2) Production of Electricity

Electricity by definition is electric current that is used as a power source!

This electric current is generated in a power plant, and then sent out

over a power grid to your homes, and ultimately to your power outlets.

Electricity

Electricity is very important in our lives.

We would find it very hard to do without it.

There are so many things in our homes that are powered by electricity that we have begun to depend on them.

Imagine you woke up this morning and had no electricity.

What difference would it make to

your normal morning routine?

What is Electric Current

The movement of charges such

as electrons is called current, and

this electrical current is what

powers household appliances.

Electric Current =Charge Passing

Through A Given Area

-------------------------------

Time

So How Is An Electric Current Generated?

Electric current generation - whether from fossil fuels, nuclear, renewable fuels, or other sources is usually

based on the:

Simple Equation

For

Electricity Generation

Motion is Essential

If you place a magnet and a conductor (copper wire), in a room together

there will be no electric current generated. This is because motion, from our equation for electricity, is

missing! An electric current is not generated unless the magnetic field

is moving relative to the copper wire, or the copper wire is moving

relative to the magnetic field.

When the number of forest are reduced and the forested area is curtailed, deforestation takes place. It is generally accepted that for a balanced environment and economy about 25% of the land area should be under forest

Forests are cut down to meet the demands of industry because wood is required as construction material for building.

In Pakistan nearly 50% of heating and cooking requirements are met by 20.88 cubic metres of fuel wood every year. In fact, 76% of the rural population depends on wood for heating and cooking which results in excessive cutting of trees.

Deforestation destroys the habitats of millions of species of plants and animals that will need the areas of forest to survive. Thus, it may lead to the extinction of these species, causing havoc in the biological food chains and the delicate balance of the ecosystem of these areas. ppollution will be increaseDestruction of wildlife habitation

more pollution as roads will be built near by which vehicles will

DISADVANTAGE:

Flooding also causes of the deforestation. The removal of the tress adds to the high level

of the carbon dioxide in the atmosphere.

ADVANTAGES:

Deforestation provide the material for various industry.

Cutting down tress provide a source of energy.

ADVANTAGE:

Tress are important to the water cycle. They absorbs rainfall and produce water vapor that is released in the atmosphere.

Being deforestation we should convert forest land into agricultural land.