Study material

दुनिया के ये टॉप 10 आविष्कार जो भारत ने किए Ujjawal Prabhat बहुत से लोग यह मानते या कहते पाए गए हैं कि पश्चिम ने विश्व को विज्ञान दिया और पूर्व ने धर्म। दूसरी ओर हमारे ही भारतीय लोग यह कहते हुए भी पा...

   ENVIRONMENTAL SCIENCE  Subject Code: BESE0-101        L T P C                       Duration: 48 Hrs. &n...

Q. What do you mean by population inversion ? :- Making   N2 > N1 i.e., the number of particles N2 more in higher energy level than the number of particles N1 in lower energy level is called ...

Q. What do you mean by radiation induced losses ? :- When the glass molecular matrix interacts with electrons, neutrons, gamma rays and x-rays, the structure of the glass molecules is altered and the...

Q. What are bending losses ? :- Bending losses are of two types : (i) Micro-bending losses :-micro bending losses occur due to the fact that the small bends cause scattering which cause mode-coupling...

Q. What are the different losses that take place in an optical fibre ? :- (i) material absorption     (ii) scattering    (iii) mode coupling    (iv) Leaky modes &nb...

Q. What is meant by transit - time dispersion ? :- The dispersion sets an upper limit on the rate at which the light can be modulated by an analog or digital electrical signal. Due to this distortion...

Q. What are the attractive features of optical fibres ? :- The main attractive features of optical fibres are: (i) low signal loss  (ii) high band width (iii) small size and bending radius (iv) ...

Q. Define acceptance angle ? :- If any light wave impinging on the core within a certain angle of incidence gets coupled into the fibre and propagated, then this angle of incidence is called acceptan...

Q. What idea does numerical aperture give ? :- Numerical aperture of the optical fibre is a measure of the light gathering power of the fibre and determines the angle of the "light acceptance co...

Q. What are the advantages of optical fibers in communication systems ? :- Optical fibres offer some important advantages over wires : 1. Light travels faster in glass than electrical signals in the ...

Q. What are the conditions for total internal reflection ? :- The following conditions should be fulfilled for total internal reflection to take place at the fibre walls : 1. The core must have a sli...

Q. How is the propagation of light taking place an optical fibre ? :- When light enters at one end of the fibre under required condition, most of light will propagate or move down the length of fibre...

Q. What do you mean by graded  index  fibre ? :- If the core of optical fibre has a non-uniform refractive index, gradually decreasing from the center towards the outer region, it is called...

Q. What is a step index fibre ? :- If the core of optical fibre has uniform refractive index, it is called a step index fibre.             Step Index Fiber Opt...

Q. According to modern English grammar Noun is divided into how many parts ? :- According to modern English grammar Noun is divided into two parts. (a) Concrete Noun ( ठोस संज्ञा/छूआ जानेवाला संज्ञा...

Q. According to countability Noun is divided into how many parts ? :- According to countability Noun is divided into three parts . (i) Proper Noun (ii) Countable Noun /  Count Nouns (...

Q. What is LASER ?                 :- LASER (Light Amplification by stimulated Emissions of Radiation ) is a device within which photon multiplication by stimu...

Q. What is an optical fibre ?      :- It is a narrow cylindrical structure of glass core surrounded by a cladding of slightly lower refractive index. The core diameter usually varies ...

Q. What is a fiber wave guide ? :- A fiber wave guide is a very thin long cylinder composing of two circularly symmetric cylinder elements with different refractive indices . The inner cylinder of hi...

Q. What do you understand by fiber optics ? :-  Fiber optics is the branch of physics pertaining to the propagation of light through thin filaments of transparent material and includes tran...

Q.  What is a modes ? :-  A mode is a stable propagation state in an optical fibre. If light travels through an optical fibre along certain paths, the electromagnetic fields in the light wa...

Q. What are the difference between insulators and dielectric ? :- Material like ceramic, polymers and paper are non-conducting in the nature. When these materials are used for electrical insulation, ...

Q. What is gradient of a scalar field ? :- Gradient of a scalar field is a vector quantity whose magnitude is equal to the maximum rate of changes of scalar field and is directed along the normal to ...

Q. What do you understand by electromagnetic waves ? :-  Electromagnetic waves are coupled electric and magnetic oscillations that moves with the speed of light and exhibit typical wave behavior...

Q. What do you understand by pointing vector ? :- pointing vector is defined as the vector product of electric field and magnetic field vectors , which gives the time rate of flow of wave energy per ...

Q. What is fields ? :-  The region in which the function specifies the physical quantity is called a field. * In electricity and magnetism two commonly terms used are . (i) Scalar field (ii) Ve...

                                  NOUN ( संज्ञा ) Q. What is Noun ? :-  Noun is a naming word.    O...

Q. Father of English Essay                                             :- franc...

Q. Father of English Drama                                       :-William Shakespeare *why is ...

Q. Father of English novel                                              :- Deniel De...

Q. Father of English Grammar                                                 :-...

Q. Father of English language, poetry & short story                    :-  Geoffrey Chaucer Ali * Geoffrey Chaucer. He was born in London ...

                                     Laser Laser ( Light Amplification by Stimulated Emissions of Radiat...