Saturday, July 14, 2012

Trading a/c balance sheet from trial balance std 11 GSEB


Q - 6
Prepare Trading a/c , P/L a/c and Balance sheet from balances of trial balance given as below for the year ending 31-3-06 for Shri Ram.
Trading A/c Balance sheet from Trial Balance sheet Ch-2 Ex 6
Trading A/c Balance sheet from Trial Balance sheet Ch-2 Ex 6
Free Download Presentation 
Chapter - 2 Example 6 

Prepare Trading A/c and P/L A/c from balances of trial balance std 11


Q-5
Prepare Trading a/c and P/L a/c from balances of trial balance given as below for the year ending 31-3-05 
for shri sahil.
Ch-2 Ex 5 Trading A/c  Profit loss A/c from Balance sheet
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  Presentation :  Prepare Trading A/c and P/L A/c from balance of Trial balance


Trial and profit loss Ac Std 11 Accounts Ch 4 GSEB course

Q -4
Prepare Trading a/c and P/L a/c from balances of trial balance given as below  for the year ending
31-3-04 for shri saumil.

Chapter-2 Example 4 Trial and Profit and Loss Account for std 11
Free Download Powerpoint presentation
of Example which is most useful to understand Accounts entry.

Saturday, June 30, 2012

Plasmolysis through the effect of Isotonic for std 10 to 12


Practical-2
AIM :-
Study of Plasmolysis through the effect of Isotonic, Hypotonic as well as Hypertonic Solutions
of Sodium Chloride and  Potassium Chloride on Mounted Epidermal Cells of Tradescantia leaf.
INSTRUMENTS AND MATERIALS : -
Slide, Cover slip, Microscope, Dropper, Blotting paper, Tradescantia leaf, Water, Glycerine, NaCL solution, KCL solution.
Plasmolysis through the effect of Isotonic for std 10 to 12

Conclusion :-
This a kind of exosmosis. When living plant cell is placed  in a concentrated solution of sugar or salt plasmolysis is induced in them. Normally living cells are turgid as concentrated of vacuolar sap is lower than the surrounding solution water from the cell starts moving outside through exosmosis.

Sunday, June 17, 2012

Oxygen is evolved during photosynthesis. Std 10 to 12


AIM :  To show that oxygen is evolved during photosynthesis.


PRINCIPLE :  During photosynthesis photolysis of water takes place  and oxygen is released.
Equation for oxygen evolved during photosynthesis.
MATERIALS       :  Beaker, funnel, test tube, twig of Hydrilla, water.
  
Oxygen evolved during Photosynthesis

Bubble comes out 

Oxygen evolved during photosynthesis
Result :
Air bubbles released from the cut end of plant twigs move up through the funnel and get collected in the test tube.
Conclusion :
The oxygen produced during photosynthesis moves up in thee form of bubbles and getts collected in the test tube.
Application : 
During photosynthesis oxygen evolved and released in the atmosphere. It can be shown to the students by the above experiment.           

Saturday, June 16, 2012

Stomata in Lower Epidermis of leaf, Biology std 10 to 12

To study the stomata present in the epidermis of leaf by preparing a temporary slide.

AIM :   To study the stomata present in the epidermis of leaf by preparing a temporary slide.

PRINCIPLE :  As the lower epidermis is not directly exposed to sunlight it contains more number of stomata. This reduces the rate of transpiration.
MATERIALS :  Leaf of Hibiscus, Nagervel (betel leaves) or Maize, slides, forceps, scalpel or blade, Microscope

Lower and Upper Epidermis of Nagarvel leaf.

Scratch of Nagarvel leaf on Lower epidermis

Stomata view in Microscope.

Stomata viewed in Microscope

Enlarge view of  stomata.
Result
Maximum number of stomata are visible as the lower epidermis has more number of stomata. In Hibiscus and Nagarvel the guard cells of stomata are been shaped while in Maize they are dumb-bell shaped.
Conclusion :
By this method stomata can be seen and counted under the microscope.
Application :
This is an easy method to show the stomata to the students.



Sunday, June 10, 2012

ISOTOPES AND RADIO-ISOTOPES Science for 8 to 12



Isotopes : 
 Atoms of a given element, have the same atomic number, that is they contain the same number of protons. However, they may contain different numbers of neutrons. They correspond to the same element and are chemically indistinguishable; they have different mass numbers 
(Iso means same, tope means same place; they occupy the same place in the periodic table).


Therefore atoms of the same element having same number of protons 
(atomic number but different number of neutrons (different mass numbers), are called isotopes. Isotopes may be naturally occurring or artificially made.

Example : Normal hydrogen (protium) 1H1 deuterium 1H2 and tritium 1H3 are the isotopes of hydrogen. 6C11, 6C12 and 6C14 are the isotopes of carbon. Uranium has two isotopes namely 92U235 and 92U238.

Radio-istopes : The term radio-isotope is the shortened from of radioactive isotope. If the isotope of an element is radioactive, then the isotope is called. radio-isotope, referred to as radio-nuclide. At least one radio-isotope of every element is available. Over a thousand of them can be made artificially, mostly in nuclear reactors using slow neutrons as bombarding particles.

Examples : Cobalt-60 an isotope of cobalt is radioactive; It is usually refereed to as radio-cobalt. Radio-iodine (I131), radio-iron (Fe59) radio-sodium (Na24), radio-phosphorous (P30), radio-cobalt (Co60), radio-sulphur (S35) and radio-carbon (C14) are some of the radio-isotopes.

Uses of Radio – Isotopes : Radio-isotopes find applications is various fields, some are listed below.
Radio-phosphorous is used in agriculture to determine the kind of phosphate required for a given soil and crop.
Radio-iodine is used in the treatment of overactive thyroid glands and radio-cobalt in the treatment of cancer, Radio-sodium is used to study the action of medicines.
Radio-cobalt or radio-iridium is used in industry to check machine parts.
Radio-carbon is used to estimate the age of fossils and archaeological specimens.

POINTS TO REMEMBER
 Spontaneous disintegration of certain unstable atomic nuclei with the emission of certain radiations is called radioactivity.

 Becquerel rays are the radiations emitted by radioactive elements.

 The elements from atomic number 81 to 92 are found to be radioactive.

 The radioactive radiations are alpha (alpha) particles, beta (beta) rays and gamma (Gama) radiations.
  (alpha) - particles are nothing but helium nuclei, 
- rays are stream of electrons and 
- radiations are high energy photons.


 The changing of one element into another is known as transmutation. Original atom is parent atom and the new atom produced is the daughter atom.

 Half life of a radioactive element is the time taken by a radioactive sample of that element, to get reduced to half its mass.

 Half life varies from microseconds to billions of years.

 The phenomenon by which radioactivity is induced in an element, is called Induced radioactivity or artificial 
radioactivity.

 When a stable aluminum atom is bombarded by (alpha) particles it becomes radio phosphorus.

Atoms of the same element having same number of protons (atomic number) but different number of neutrons (different mass number) are called isotopes.

Isotopes of Hydrogen are Normal Hydrogen (protium) (1H1), Deuterium (1H2) and Tritium (1H3)
Isotopes of Carbon are 6C11, 6C13, and 6C16,
Isotopes of Uranium are 92U235 and 92U238

It the isotope of an element is radioactive, then the isotope is called radio isotope, referred to as radio nuclide. Radio nuclides are manufactured in nuclear reactors.