Light Emitting Diode :- It is a heavily doped p-n junction which under forward bias emits spontaneous radiation. The diode is encapsulated with a transparent cover so that emitted light can come out. LEDs are biased such that the light emitting efficiency is maximum. The reverse breakdown voltages of LEDs are very low, typically around…
p-n Junction Diode :- A p-n junction is a boundary or interface between two types of semiconductor materials, p- type and n- type inside a single crystal of semiconductor. It is the basic building block of semiconductor device like p-n junction diode. p-n Junction Diode under forward bias :- When an external voltage V is…
Semiconductors :- Semiconductors are those material which has the conduction properties in between conductor and insulator. It means semiconductor do not allow the free electron to flow as conductor. Examples :- Silicon (Si), Boron (B), Carbon (C), Germanium (Ge) etc. The reason for such type of conductor is the small gap between the valence band…
Nuclear Reactor :- A nuclear reactor is a device used to initiate and control a self sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation an in nuclear marine propulsion.
Nuclear Fusion :- It is a nuclear process in which two light (small) nuclei fuse to form a larger nucleus, energy is released. Examples :- ₁H¹ + ₁H¹ → ₁H² + e⁺ + v + 0·42 MeV ₁H² + ₁H² → ₂He³ + n + 3·27 MeV ₁H² + ₁H² → ₁H³ + ₁H¹ +…
Nuclear Fission :- Nuclear Fission is a reaction wherein a heavy nucleus is bombarded by neutrons and thus become unstable, which causes decompose or split into two nuclei with equivalent size and magnitude, with a great detachment of energy and the emission of two or three neutrons. Example :- Isotope ₉₂U²³⁵ bombarded with a neutron…
Properties of Alpha Beta and Gamma Rays :- During radioactive decay, particles like alpha, beta and gamma rays are emitted by the unstable atoms like uranium, thorium, polonium, radium, actenium etc to gain stability. Properties of Alpha Rays :- Properties of Beta Rays :- Properties of Gamma Rays :-
Radioactivity :- Henry Becquerel discovered radioactivity in 1896 by accident. Experiments performed subsequently showed that radioactivity was a nuclear phenomenon in which an unstable nucleus undergoes a decay. Becquerel studying the fluorescence and phosphorescence of compounds irradiated with visible light, the observed an interesting phenomenon. After illuminating some pieces of uranium-potassium sulphate with visible light…
संक्रामक रोग :- वैसे रोग जो प्रत्यक्ष या अप्रत्यक्ष रूप से एक व्यक्ति से दूसरे व्यक्ति में फैलते हैं, उन्हें संक्रामक रोग कहते हैं| ऐसे रोग सूक्ष्मजीवों से होते हैं| सूक्ष्मजीव रोगी के शरीर में वृद्धि करते हैं और शरीर को रोग का आश्रय बना देते हैं| संक्रामक रोग के लक्षण :- शरीर के ताप…
अच्छे स्वास्थ्य की आवश्यक शर्तें निम्नलिखित हैं :- किसी व्यक्ति का स्वास्थ्य अच्छा तब होता है जब वह सभी प्रकार की बीमारियों से मुक्त हो एवं शारीरिक या मानसिक सभी कार्य प्रभावी ढंग से करता हो। अच्छे स्वास्थ्य की मूल शर्तें निम्नलिखित हो सकते हैं – 1. संतुलित आहार (Balanced diet) :- वैसा आहार जिसमें…
मलेरिया (Malaria) : मलेरिया एक संक्रामक रोग है जो प्रोटोजोआ समूह के सूक्ष्मजीव “प्लाज्मोडियम” के संक्रमण से उत्पन्न होता है। प्लाज्मोडियम की चार प्रजातियां होती है – मलेरिया कैसे फैलता है? इन कारणों से मलेरिया किसी मनुष्य के शरीर में फैलता है : मलेरिया के लक्षण (Symptoms of Malaria) : मलेरिया के लक्षण निम्नालिखित हैं…
Mass Defect and Nuclear Binding Energy :- The actual mass is always less than the sum of the individual masses of the constituent protons and neutrons because energy is removed when the nucleus is formed. This energy has mass, which is removed from the total mass of the original particles. This mass, known as the…
