Fear of Examination

Fear of examination is not exactly the fear in the true sense but it is something  pro activeness in the minds of students  to combat the challenges of examination.

Students prepare for the examinations days and months in advance. The day of the examination is always awaited with a mixed feeling. There is a fear of facing a tough paper and there is also a sense of relief to know that once the papers are over, there can be enough time to play and enjoy.

Outside the exam hall students hold on to their books, notes and pencil boxes. They are seen pacing up and down the corridors trying to absorb as much as they can from their books up to the last minute. Some students read loudly while others prefer to sit silently in a corner and concentrate on their notes. Some students are seen discussing questions with classmates. Some faces show panic and fear, others show composure and confidence.

Once the students enter the exam hall they surrender all their books and notes to their teachers. There is lot confusion as they try to locate their roll numbers on seats. The invigilators usually guide the students to their seats and soon order is restored in the class room. The examiners and invigilators advice the students to remain silent while the examination is on. As time passes, students keep a close watch on watches. Even the invigilators keep warning the students about the time.

  Maths is not a subject , it is a habit like our daily activities eating , sleeping and many more. As per my experience which students deal it as a game or fun as their habit , after aomestime they become champion for it . I have seen there are two type of students 1. Who take it as their habit , after some they become champion 2. Who take it as a subject , they always try to deal it as other subjects and they finds several difficulties to raise their logical power by this subhects.   So it is my best suggestion for students to death this subject as a habit , for that they should solve problems at least one hour every  day which can make them as a champion in maths....

Endothermic reaction : Any chemical reaction that absorbs heat from the environment is termed as an endothermic reaction. The absorbed energy provides the activation energy for the reaction to occur.

Example : Mixing water ( H2O ) with Potassium Chloride ( KCl ) is an example of endothermic reaction.

Photosynthesis is also an example of endothermic reaction. Here Chrolophyll is used from sunlight to react water and carbon dioxide ( CO2 ) to make Glucose and Oxygen ( O2 ).

Note : Endothermic reaction results in cooling of environment.

Exothermic reaction : Any chemical reaction that releases heat to the environment in the form of heat or light is termed as exothermic reaction. Exothermic reactions may be warm or explosive.

Example : Any combustion reaction, respiration , rusting of iron etc are some of the examples of exothermic reaction. In these cases heat is released as a result of exothermic reaction.

Note : Exothermic reaction is exactly the opposite of endothermic reaction.

Newton's Universal Law of Gravitation states that

Any two objects exert a gravitational force of attraction on each other.

The direction of the force is along the line joining the objects. 

The magnitude of the force is proportional to the product of the gravitational masses of the objects and inversely proportional to the square of the distance between them.

F=GMmr2">F

=GMm/r^2

where F">F represents the force in Newtons, 

M">M and m">m represent the two masses in kilograms,

and r">r represents the separation in meters. 

G">G represents the gravitational constant, which has a value of 6.674⋅10−11N(m/kg)2">6.674*10^−11N(m/kg)^2.

Because of the magnitude of G">G, the gravitational force is very small unless large masses are involved.

WRITING CHEMICAL FORMULA-

*The Chemical Formula is a representation of a substance [element or compound] by means of the symbol.                                             THE RULES FOR WRITING CHEMICAL FORMULA ARE-

*The Symbol Of the elements ^should be known.

*The Valency of the elements should be known. 

SOME ELEMENTS WITH POSITIVE AND NEGATIVE VALENCIES-

+VE VALENCY    ELEMENT  SYMBOL   ION

V-1                     Potassium    K              K¹⁺

                           Sodium           Na            Na¹⁺

V-2                     Calcium          Ca            Ca²⁺

                          Magenisum     Mg           Mg²⁺

V-3                    Aluminium       Al             Al³⁺

-VE VALENCY    ELEMENT    SYMBOL    ION

V-1                   Chlorine           Cl                Cl^1-

                          Bromine           Be               Br^1-

V-2                    Oxide                O                O^2-

                          Sulphide           S                 S^2-

V-3                    Phosphate      Po_{4                PO4^3-}

precision = It is defined as the repetitiveness of a result is known as precision.
Example- The standard value of frequency in India is 50hz during the experiment of 10 time you are getting result of 46,46.5,46,45.5,46,46,46,49,46,46
result 46 is the precision result
Accuracy- Closeness toward the standard result is known as accuracy
49 is accurate but not precise