Class - 10 (biology) Science

-

Electricity 

Matter is composed of atoms. Electric charge, just like mass, is the basic property of a matter. 

Charge originate in an atom, in which its most familiar Carriers are the electron and proton. There are two types of charges. 
1. Positive 
2. Negative 

Charge carried by an electron is deemed negative and that carried by a proton is positive. 
By convention the charge acquired by glass rod with silk is called positive charge. 
While the charge produced on an ebonite road when it is rubbed with a wollen cloth is called negative charge. 
A body gets positively charged when it loses electrons and negatively charged when it gains electrons.

Properties of electric charge 

1. Like charges  

      Like charges repel each other l, while unlike charges dissimilar or opposite or of different type attract each other.

It means that a positive charge and a negative charge repels a negative charge. On other hand a positive charge attracts a negative charge. 

2. Quantisation of charge 

Charge in body is produced due to excess or deficiency of electrons 

3. Conservation of charge

The total charge of an isolated system always remains constant. Electric charge can neither be created nor destroyed. It may be transferred  from one body to another.

4. Coulamb's law

 The force of interaction between the two charges is directly proportional to the product of two charges and inversely proportional to the square of the distance between them. 


 Conductors & Insulators 

Substances can be classified on the basis of their ability to conduct electric charge through them. 
All substances classified into two categories:

1. Conductors:

The substances through which electric charge can flow easily are called conductors.  

2.Insulators:

The substances through which electric charge cannot flow are called Insulators. 

Electric current 

The movement of electric charge is known as an electric current.

An electric current is Expressed by the amount of charge flowing through a particular area in unit time. 

          OR

It is the rate of flow of electric charges.

              I= Q/ T

Unit of electric current = The s.I unit of electric current is Ampere (A). 

When one Coulomb (1C) of charge passes through a cross-section of  a conductor in one second (1s), the electric current flowing through it, is called one ampere (1A).
 
     1. Milliapmere,     1mA = 10^-3A
     2. Microampere    1  A  = 10^-6A

An instrument used to measure electric current is called ammeter.

Definition of coulamb

Ampere is one of the seven base units of SI,.definition of a coulamb can be derived from ampere.
                           1C = 1A ×1s
 
The quantity of charge which flows through a circuit when one ampere (1A) of current flows through it in one second (1s), is called coulamb (1C) of charge. 

Direction of current :
        The direction of an electric current is taken to be the direction of flow of the positive charge. Since in an actual metallic conductor, the current is carried by the free electrons, the conventional current is in a direction which is opposite to flow of electrons.

Electric potential and potential difference:

The electric potential energy per unit charge is called electric potential. The electric potential at infinity, is taken as zero.

Electric potential at a point in an electric field is defined as the amount of work done in bringing a unit positive charge from infinity to that point.

  Electric potential = work done/charge

Electric potential is a scalar quantity and is denoted by letter V.

Unit of electric potential: The total amount of work done in bringing a charge from infinity to a point, then the electric potential.







   

Comments

Post a Comment

Popular posts from this blog

Class 10 Science (Biology) Heredity and Evolution

-
Image
~ INTRODUCTION  In the last chapter you have studied how organisms reproduce to produce new individuals. The offsprings produced as a result of reproduction are similar to their parents as well as other individuals of the species. For example, man resembles man in body shape size etc. Similarly dogs resemble dogs,  cows resemble cows, and so on. Similarly the plant obtain from the seed of a mustard plant is similar to its parent. The offspring plant is similar to other mustard plants as well. But how is it that the offsprings are similar to other members of the species as well as to Parents. All this happens because of the presence of genes in parent/parents which are transferred to the next generation via  gametes or other means. These genes transfer the biological information of parents to offsprings which gives rise to various characteristics in the offspring thereby making them similar to parents or other members of species.  These differences in characteristics ...
Read more

National anthem, National song, National Bird , National animal, National game, national flower, first' president, first prime minister, Republic day , independence day.

-
Image
1. Who composes the national anthem? Ans. Rabindranath Tagore. 2. Who composes the national song? Ans. Bankim Chandra Chatterjee. 3. Which is national flower? Ans. Lotus. 4. Which national Animal? Ans. Tiger 🐅. 5. Which is national game? Ans. Hockey 🏒. 6.which is national song?  Ans. Vande maataram. 7. Which is national bird? Ans. Peacock 🦚. 8. Which is national fruit? Ans. Mango 🥭. 9. Who was first prime minister of India? Ans. Pandit Jawaharlal Nehru. 10. Who was first president of India? Ans. Dr. Rajendra Prasad. 11. When was Independence day celebrated? Ans. 15 August  every year.  12. When was Republic day celebrated? Ans. 26 January every year.
Read more

Chapter 7 control & coordination class 10th

-
Image
  Stimuli The changes in the environment or environmental factors to which the organisms respond and react are called stimuli. Coordination The working together of the various organs of an organism in a systematic manner so as to produce a proper reaction to the stimulus, us called coordination. System functions by the release of chemical messengers -- the hormones and is called endocrine system and the other works by the Conduction of nerve impulses like the Conduction of an electric current and is called nervous system. ANIMALS-- NERVOUS SYSTEM The system by which controls and coordinates all the activities of various parts in response to external and internal stimuli by the Conduction of nerve impulses is called nervous system. Sense organs Name of receptors     stimulus    location Photoreceptors             light             Eyes Phonoreceptors          ...
Read more