Thermal power stations:

Thermal power stations are set up near coal fields to avoid wastage of transport.

Coal is burnt in power stations

Heat produced is used in heating water

Water is converted to steam

Steam has capacity to rotate turbines

Turbines are connected to generator

Generator produces current

                 Advantages:                                        Disadvantages:

1.large amounts of energy is produced   1.cause pollution

2can be used for commercial purpose     2.liberates smoke and ash

                                                                        3.non renewable source

Questions;

1.why thermal power stations are near coal fields?

2.Define fossil fuels and give egs?

3.What are major limitations of fossil fuels?

4.What is calorific value of coal and its ignition temperature?9500kj/kg&1977 c

5.what is energy transformation occurring in thermal power stations?

6.what are 4 types of coal?

7.whar happens on combustion of coal and write its reaction?

8.what is difference between coal and coke?

9.which is better fuel c₂H₄ or c₂H₂ ?

magnetic field and lines of force work sheet

Magnetic field

Definition:space around thwe magnet in which its influence can be felt is called magnetic field.

Denoted by: B

Formula:F=mB

Units:oersted,tesla,guass

Consists of:lines of force

Element of magnetic field:dip,declination.

Lines Of Force

Definition:line along which a freely suspended north pole tends to move is called magneticfeild.

Properties of magnetic field;

1.outside the magnet they move from north to south.

2.inside the magnet they move from south to north.

3.they are closed and curved.

4.ther are crowded at poles as poles nare stronger.

5.no two lines of force will ever intersect because if they intersect field is in two directions which is not possible.

Questions on magnetic field and lines of force:

1.why field lines are crowded at poles?

2.define dip and declination?

3.define pole strength and its units?

4.why 2 lines of force will never intersect?

5.why earth behaves as giant magnet?

6.what is sure test of magnetism?

7.how does freely suspended magnet aligns?

8.what are the ferro,para and  diamagnetic substances.give egs of ferromagnetic substances?

9.draw figures of lines of force for uniform magnetric field ,2 magnets with like poles facing each other and unlike poles facing each other?

10.what do you mean by permeabiloity of the medium and what is its value?

11.what is magnetic flux?

12.what are 3 different ways to produce magnetic field?

13.what does tangent at a point on line of force indicate?

14.can we separate two poles?

15.what is difference between gravity and magnetism?

16.what is difference between longitudes and lines of force?

17.describe an activity and how to draw lines of force?

18.what is neodymium and its composition?

19.what are electromagnets give eg?