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EDS Prepratory Notes
Reflection of Light:
When a beam of light travelling in a straight line homogeneous medium falls on the boundry of another medium, then a part of it bounces back from there, this bouncing back of the light is called the reflection of light. Dependence of reflection of light The amount of light reflected from the surface of another medium depends on
Spherical Mirrors A spherical mirror is portion o the reflecting surface of a hollow sphere. Types
SOME IMPORTANT DEFINATIONS
USES OF SPHERICAL MIRRORS CONCAVE MIRRORS
CONCAVE MIRRORS
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The bending of light when it enters from one medium to another is called refraction of light. LAWS OF REFRACTION There are two laws of refraction of light.
CONDITION FOR REFRACTION
APPLCATIONS Refraction of light may have given us false visual impression , but it does have many useful applications .Lenses are used in magnifying glasses,spactacles,microscopes, telescopes and overhead light rays passing through them produce the required images. APPARENT AND REAL DEPTH When we view an object at the bottom of a swimming pool, the object appears closer to the surface. This aparent depth is caused by refraction of light. It occurs due to fact the rays from an object under water do not travel straight to the eye but are refracted away from the normal as they leave the water surface. When these rays are produced backward, they meet and their images is formed so that the observer sees the object as that it were at the point of formation of tages. APPARENT DEPTH The distance of image from the surface of the water is called apparent depth. REAL DEPTH The distance of object from the surface of water is called real depth. TOTAL INTERNAL REFLECTION When a ray of light from denser medium enters a rare medium in such a way that the angle of incidence is greater than the critical , then they reflects totally inside and does not emerges out from the denser medium.This phenomenon is called Total internal reflection When the value of angle s of incidence becomes greater than the criticale angles the rays does not pass into the second medium i.e the ray of light no longer suffer refraction but totally reflected back in the danser medium obeying laws of reflection. Conditions for total internal reflection
Dispersion of light The phenom of splitting of white light into its colours is called dispersion of light. The refraction of light depends on their wavelength.Since the sunlight consists of different colours the waves of different wavelength obtained. Therefore when light passes through a prism then the wave of different wavelength deviate on different paths due to dispersion of light. The band of colours which is seen on the the screen due to passage of sunlight through the prism is known as solar spectrum.. RAINBOWS An arc of spectral colours, which appears in the sky after the rainfall is called rainbow. How rainbow is formed? Rainbow is solar spectrum produced due to dispersion of light. After the rainfall, innumerable droplet of water remain suspended high up in the air. When sunrays fall on these droplets each droplet behaves likes a prism and light rays enterig, the droplets suffers refraction and total internal reflection. Since these rays are white light, they split into seven colurs. CONDITIOn Rainbow is the most beutifu and colourful natural ph whcih can be seen on the sky. The viewers can see the rainbow when the sun is at the back of the observer. When sunrays fall obliquely. Rainbow can be seen in the morning or in evening. TYPES OF RAINBOW 1.Primary Rainbow Such rainbow has brightest colours and is easily visible . Characteristis
2.Secondary Rainbow Such Rainbow which is fainter than primary and is seldom visible called secondary rainbow. Characteristis
Continue Note:If there is any error(s) kindly correct me. |
#2
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Really good try,,, kindly make such effort for computer nd solar system. Thank you
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Saqib Riaz (Sunday, January 17, 2010) |
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Atomic And Nucleur Physics
Atomic And Nucleur Physics
Structure of an Atom An Atom consists of two parts i.Nucleus ii.Extra Nucleur space i.Nucleus Nucleus occupies only a small fraction of the total volume of an atom and is at the centre of an atom. The two main particles of nucleus are the positively charge proton and neutron with no charge. The mass of both is almost equal and is 1.67 x 10-27 kg. ii.Extra Nucleur Space In this space negatively charged particlle (electron)moves around the nucleus in orbits of various shape. The mass of an electron is 9.1 x 10-31 kg ATOMIC NUMBER The number of protons in the nucleus of an atom is called atomic number. It is denoted'Z'. It is also called charged number. MASS NUMBER The total number of protons and electrons in the nucleus of an atom is called mass number. It is denoted by 'A' The no's of nuetron"N" present in nucleus is given by. Quote:
wch is called the nucllide. For example there is only one proton in the nucleus of H atom so its atomic no is 1 and atomic mass number is also 1 . ISOTOPES Isotopes are those elements whose atomic numbers are same but their mass number are different. For Example Hydrogen has three aisotopes represented by Quote:
TOMIC NUMBER
ATOMIC MASS NUMBER
NATURAL RADIOACTIVITY Radioactivity is such a process in which the elements with the charge number(atomic number)greater than 82 naturally keep on radiating. Radioactive Element Element which have charge number greater than 82 are unstable and they emit radiations continuously. Such types pf elements are called radioactive elements. Characteristics
Radioactivity was discovered by Henry Becqueral in 1986. He found that an ore containing Uranium emits an invisible radiation that penetrates through a black paper wrapping a photographich plate and affects the plate. In order to test his conclusion ;he performed many experiments. Bacqueral took a closed box into which no light could enter and placed in it the uranium salt and photographic plates near to each other and also seprated by Aluminium sheets. In both the cases he obtained the same results. This shows that uranium salt emits strong radiation and they are not affected by the absence of presence of the sunlight. Artificial Radioactive Elemenets Using modern techniques, the elements whih are much lighter than the natural radioactive elements are made radioactive. Such elements are called artificial rdiactive elements. Thus we include that all the radioactive from the radioactive material are not alike these are of 3 types , namely Alpha, Beta and Gamma radiations. (α)Alpha Particles The radiations that bend towards the negative plate of magnetic field and are composed of positively charged particles called α particles. Properties
β(beta)-Particles The radiations that bend towards the positive plate of magnetic field are composed of negative charged particles called β-particles. Properties
Gamma Particles Thse radiations that go straight without bending means that having no charges are called gama particles. Properies
HALF LIFE The time during which the number f atoms of an element are reduced to one half is known as half life of an element. We know that radioactive elements continuously emit radiations due to which they changes into new elements.
Parent and Daughter Element During radiation emission reaction, the original element is called the parent element and newly formed element is called the daughter element.The number of breaking atoms is proportional to the no of atoms left in that element.this means that no of initially breaking atoms is large which decreases with time. NUCLEAR FISSION REACTION The breaking of nucleus into two parts wih the release of large amount of energy is called nuclear amount of energy is called nuclear fission reaction Types of Nuclear Fission Reactions There are two types of reactions 1.Controlled Fission Reaction 2. UnControlled Fission Reaction Controlled Fission Reaction A system in which the fission reaction is controlled is called a controoled fission reaction. If the fission reaction is controlled then the desired amount of energy can be produced in a useful manner.In the nuclear reactor. Boron or Cadmium rods absords the sur neutrons and thus nuclear fission reaction can be controlled. UnControlled Fission Reaction In the chain reaction as the fission reaction builds up the liberat energy goes on increasing. Th fission reaction thus become uncontrollable and hence whole of the matter explodes which resluts in great destruction. Such a reaction is used in atomic bomb. NUCLEAR FUSSION REACTION AProcess in which the light nuclei diffuse to form a heavier nucleus is called fusion reaction During the fusion reaction mass is converted in to energy, which is subsequently released mainly as heat and other forms of energy. Th energy output of such fusion process is even larger than that released during nuclear fission reaction. Difficult to produce Fussion reaction. It is very difficlut to produce a fussion reaction because when nuclei are brought near each other for fusion , work has to against the elctrostatix force, which requires amount of energy or heat. Source of solar energy Scientist considered that the energy commimg from the sun and the stars is due to fussion nucleons.For producing alpha particles hydrogen has to be converted into helium. Hydrogen Bomb is an example of fussion reaction.For fussion reaction the required temprature is achieved by exploding an atomic bomb. uDIFFERENCE BETWEEN FISSION AND FUSSION REACTIONS FISSION REACTION
FUSSION REACTION
Continue Kindly correct me if sime error is done.
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Always do what you are afraid to do Saqib Riaz(TIPO KHAN) |
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Thank you Saima.Inshallah i will try to post the topics which you asked for....
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Always do what you are afraid to do Saqib Riaz(TIPO KHAN) |
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Gold Engr (Saturday, September 25, 2010) |
#5
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@saqib riaz
i really liked the way u posted material.....as it ismore comprehensible for me to learn through these bullets than mere peragraphs and articulative writings.... Urposts are appreciable.... please post some stuff in this format regarding HUMAN BODY, PRODUCTS OF SCIENCE and Universe as well.....i wud b grateful to u n liable to pay gratitudes..... Regards
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“The greatest discovery of all time is that a person can change his future by merely changing his attitude.” |
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Coordination
Nervous Coordination
Is brought aboutthrough various elements of the nervous system which are:
The stimuli are recieved by the receptors which convey the messages to the CNS through sensory neurons or nerves.CNS consolidates the information of stimuli, comprehends it and formulates the type of response to be produced. The message of type of response are passed via motor meurons or nerves to the particular effectors which produce specific response. Quote:
1.Neurons(nerve cells) The structural and functional unit of the nervous system in all animal including human is neurons.This is highly specialized cell which contins the typical orgenells found in most eukaryotic cell.This is cell highly adapted for communication because of its wire like projection, the dendrites which are often further branchedand carry impulses towards the central cell cell body.The cell body is thicker region of neurons containing the nucleus and most of sytoplasm. The axon is the projection, generally very long that carries impulses away from the cell body. Usually neurons has a single axon. Fatty substance covering the axon is myellin along with the short regions of exposed axons are called nodes of Ranvier.Many axons and dendrites combines to form a single nerve. TYPES
2.BRAIN The brain is encased in a bony shell and a further protected by three membranes or meninges.The inner part of these covers the brain and richely supplied with blood vessels. It brings Oxygen and nutritions to underlying brain and protects it. The cerebrospinal fluid(CSF) lies between the inner and middle layers which provides cushioning and ions to the brain and spinal cord. The outer most layer is tough and fibrous and provide mechanical support. The vertebrate brain is divided into three basic region a)The Hindbrain b)The Midbrain c)The forebrain a)The Hindbrain The Hindbrain is chiefly concerned with involuntary, mechanical process. It consists of three primary structures.
b.The midbrain The mid brain lies between the hindbrain and forebrain and connects the two.It processes the visual and auditory information from eyes and ears before sending them to forebrain. c.The Forebrain The forebrain is most advance in human. Its lower most part which lies above the midbrain is called Hypothalamus.
Spinal Cord The spinal cord extends from the foramen magnum at the base of the skull to the level of the first lumbar vertebra. The cord is continuous with the medulla oblongata at the foramen magnum. Like the brain, the spinal cord is surrounded by bone, meninges, and cerebrospinal fluid. The spinal cord is divided into 31 segments with each segment giving rise to a pair of spinal nerves. At the distal end of the cord, many spinal nerves extend beyond the conus medullaris to form a collection that resembles a horse's tail. This is the cauda equina. In cross section, the spinal cord appears oval in shape. The spinal cord has two main functions:
The Peripheral Nervous System The peripheral nervous system consists of the nerves that branch out from the brain and spinal cord. These nerves form the communication network between the CNS and the body parts. The peripheral nervous system is further subdivided into the somatic nervous system and the autonomic nervous system. The somatic nervous system consists of nerves that go to the skin and muscles and is involved in conscious activities. The autonomic nervous system consists of nerves that connect the CNS to the visceral organs such as the heart, stomach, and intestines. It mediates unconscious activities. A nerve contains bundles of nerve fibers, either axons or dendrites, surrounded by connective tissue. Sensory nerves contain only afferent fibers, long dendrites of sensory neurons. Motor nerves have only efferent fibers, long axons of motor neurons. Mixed nerves contain both types of fibers. A connective tissue sheath called the epineurium surrounds each nerve. Each bundle of nerve fibers is called a fasciculus and is surrounded by a layer of connective tissue called the perineurium. Within the fasciculus, each individual nerve fiber, with its myelin and neurilemma, is surrounded by connective tissue called the endoneurium. A nerve may also have blood vessels enclosed in its connective tissue wrappings.
To be continued.......
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Always do what you are afraid to do Saqib Riaz(TIPO KHAN) |
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BioDiversity
Classification of Living Organisms.
BASIS AND AIMS OF CLASSIFICATION Classification is based on such features or characters that are simmilar in one kind of organism and different in different kid of organism. The character which can be used in classification include external morphlogy, internal morphology ( anatomy), physiology, cell structure especially the number of chromosomes and chemical composition and embryology.
Aims and Objective 1. Determine similarities and differences between different organisms. 2. Arrange organism according to similarities and differences. 3. Identify the organisms on the basis of their structure and other prominent features and study them systematically and logically 4. Find out inter-relationship of organism. Units of Classification
KINGDOMS OF LIVING ORGANISMS 1. Two Kingdom System
1. FiveKingdom System[*]Margulis and Schwartz (1982) has proposed five kingdom classification.[*]This system claims to solved the difficulties faced in the two kingdom classification system. [*]According to this system all organism are classified into five kingdoms which are:
3.Kingdom-Plantae[*]The members of this kingdom are mostly multicellular autotrophs, with cellulose wall and frequently vacuolated, eukaryotic cells.[*]Chloroplasts present; principal nutritive mode is photosynthetic but some absorptive.[*]Primarily nonmotile, living anchored to a substrate. Structural differentiation; reproduction primarily sexual, e.g., Rhodophyta, Phaeophyta, Chlorophyta, Bryophyta, Tracheophyta (Pteridophytes, Gymnosperms and Angiosperms).[/LIST] 4.Kingdom-Fungi[*]he fungi include multicellular heterotrophs, such as mushrooms and molds as well as unicellular yeasts with eukaryotic nuclei dispersed in a walled and often septate mycelium[*]Fungi decompose other biological materials, develop from spores, lack plastids, photosynthetic pigments and flagella. Nutrition absorptive; chitin in cell wall. Somatic tissue differentiation absent or limited.[*] Reproductive tissue differentiation and life-cycle elaboration masked in higher forms[*]Primarily nonmotile (but protoplasmic streaming in mycelium), living embedded in a medium of food supply. Reproduction asexual and sexual both types. No embryo is formed.[/LIST] 5.Kingdom-Animallia[*]The members of this kingdom are multicellular heterotrophs with wall-less eukaryotic cells, lacking plastids and photosynthetic pigments.[*]exhibit movements and develop from embryos[*] Nutrition primarily by ingestion with digestion within an internal cavity but some- forms are absorptive.[*]Sensory neuromotory system[*]Reproduction predominantly sexual[*]They include sponges, coelentrates, insects, birds, mammals,etc.[/LIST]
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Always do what you are afraid to do Saqib Riaz(TIPO KHAN) |
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