DOCSLIB.ORG

Physics Musing (Problem Set-22) 8 Combinations) Give It an Appearance of a Liquid Drop

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Physics Musing (Problem Set-22) 8 Combinations) Give It an Appearance of a Liquid Drop edit rial Dropleton – A New Particle ? Vol. XXIII No. 5 May 2015 Corporate Office : ccording to the authors who have discovered microscopic particle Plot 99, Sector 44 Institutional area, Gurgaon -122 003 (HR). Tel : 0124-4951200 Aclusters in solids, which behave like a liquid have the properties of a e-mail : [email protected] website : www.mtg.in quasi particle. This particle has a very short life span. Stimulated by light, the Regd. Office 406, Taj Apartment, Near Safdarjung Hospital, smaller particles briefly condense into a ‘droplet’ with the characteristics Ring Road, New Delhi - 110029. of liquid water. This can have ripples. The life time of this droplet is only Managing Editor : Mahabir Singh about 25 picoseconds (trillionth of a second). Editor : Anil Ahlawat (BE, MBA) This strangely behaves like a liquid. It is thought that five electrons Contents are forming the new particle with five holes. The very short life-time of the particle, the changing positions of these particles (or electron-hole Physics Musing (Problem Set-22) 8 combinations) give it an appearance of a liquid drop. JEE Advanced 11 Practice Paper 2015 In order to evaluate and appreciate the new aspects in this experiment, I am quoting what is given in the Penguin Dictionary of Physics. Thought Provoking Problems 21 “Exciton : An electron in combination with a hole in a crystalline solid. JEE Workouts 24 The electron has gained sufficient energy to be in an excited state and Core Concept 26 is bound by electrostatic attraction to the positive hole. The exciton may You Ask We Answer 30 migrate through the solid and eventually the hole and electron recombine Target PMTs 31 with emission of a photon”. Practice Questions 2015 Any new discovery should excite our students. Our advice to our research BITSAT 42 student is this: Appreciate what others have done and learn what other Practice Paper 2015 scientists have performed earlier. Making that as a starting point, one has Brain Map 46 to go further devising your own methods and extensions. AIIMS 54 Practice Paper 2015 Anil Ahlawat Editor JIPMER 64 Practice Paper 2015 Physics Musing (Solution Set-21) 73 JEE Main 75 Subscribe online at www.mtg.in Solved Paper 2015 Individual Subscription Rates Combined Subscription Rates 1 yr. 2 yrs. 3 yrs. 1 yr. 2 yrs. 3 yrs. Crossword 85 Mathematics Today 330 600 775 PCM 900 1500 1900 Chemistry Today 330 600 775 PCB 900 1500 1900 Owned, Printed and Published by Mahabir Singh from 406, Taj Apartment, New Delhi - 29 and Physics For You 330 600 775 PCMB 1000 1800 2400 printed by Personal Graphics and Advertisers (P) Ltd., Okhla Industrial Area, Phase-II, New Delhi. Readers are adviced to make appropriate thorough enquiries before acting upon any Biology Today 330 600 775 advertisements published in this magazine. Focus/Infocus features are marketing incentives MTG does not vouch or subscribe to the claims and representations made by advertisers. All Send D.D/M.O in favour of MTG Learning Media (P) Ltd. disputes are subject to Delhi jurisdiction only. Payments should be made directly to : MTG Learning Media (P) Ltd, Editor : Anil Ahlawat Copyright© MTG Learning Media (P) Ltd. Plot No. 99, Sector 44, Gurgaon - 122003 (Haryana) All rights reserved. Reproduction in any form is prohibited. We have not appointed any subscription agent. PHYSICS FOR YOU | MAY ‘15 7 PHYSICSPHYSICS MUSINGMUSING hysics Musing was started in August 2013 issue of Physics For You with the suggestion of Shri Mahabir Singh. The aim of Physics PMusing is to augment the chances of bright students preparing for JEE (Main and Advanced) / AIIMS / Other PMTs with additional study material. In every issue of Physics For You, 10 challenging problems are proposed in various topics of JEE (Main and Advanced) / various PMTs. The detailed solutions of these problems will be published in next issue of Physics For You. The readers who have solved five or more problems may send their solutions. The names of those who send atleast five correct solutions will be published in the next issue. We hope that our readers will enrich their problem solving skills through “Physics Musing” and stand in better stead while facing the competitive exams. 22 1. A 50 kg woman is on a large swing of radius 9 m 5. A small ball of mass m moving with a velocity v that rotates in a vertical circle at 6 rev/min. What is (just before the impact) strikes a rough surface of the magnitude of her weight when she has moved frictional coefficient at an angle q with the vertical halfway up? as shown in the figure. If the vertical component (a) 522 N (b) 521 N of velocity of the ball just after impact is found (c) 523 N (d) 520 N to be (v/2) in vertically upward direction then 2. A car is moving uniformly along a circle of radius the horizontal velocity of the ball after impact in 250 3 meter with a time period of 20 seconds. horizontal direction is A stone is thrown from the car such that it again lands on the car when the car is at a diametrically opposite point in the orbit. The angle of projection of the stone as seen from the ground should be (Take g = 10 m s–2 ) (a) 45° (b) 60° (c) 30° (d) none of these 3. A hemispherical shell rests on a rough inclined plane whose angle of friction is l, then the maximum (a) vsinq inclination of the plane of base of rim from the (b) vsinq – m{(v/2) – vcosq} horizontal is (c) vsinq + m{(v/2) + vcosq} (d) vsinq – m{(v/2) + vcosq} 6. A heavy string of mass m hangs between two fixed points A and B at an angle q with the horizontal as shown in the figure. The tension at the lowest point in the string is (a) q = sin–1(sinl) (b) q = sin–1(2 sinl) (c) q = sin–1(3sinl) (d) q = sin–1(4sinl) 4. At NTP the density of a gas is 1.3 kg m–3 and the velocity of sound propagation in the gas is 330 m s–1. The degree of freedom of the gas molecule is (a) 3 (b) 5 (a) mg/(2sinq) (b) mg/(2cosq) (c) 6 (d) 7 (c) mg/(2tanq) (d) mg/(2cotq) By Akhil Tewari, Author Foundation of Physics for JEE Main & Advanced, Senior Professor Physics, RAO IIT ACADEMY, Mumbai. 8 PHYSICS FOR YOU | MAY ‘15 7. On a rough table, three blocks (including the first 9. Two balls of masses 1 kg each are connected by an block) are placed as shown in the figure. Mass of inextensible massless string. The system is resting each block is m and coefficient of friction for each on a smooth horizontal surface. An impulse of block is m. A force F is applied on the first block 10 N s is applied to one of the balls at an angle so as to move the system. The minimum value of F 30° with the line joining two balls in horizontal should be direction as shown in the figure. Assuming that the string remains taut after the impulse, the magnitude of impulse of tension is 1 kg 10 N s (a) 8 mmg (b) 9 mmg (c) 7 mmg (d) 5 mmg 30º 1 kg 8. A fixed wedge ABC in the A shape of an equilateral 5 triangle of side l. Initially, a (a) 6 N s (b) 3Ns chain of length 2l and and 2 mass m rests on the wedge 5 as shown. The chain is 60º (b) 5 N s (d) Ns 60º 3 slowly being pulled down B C l by the application of a 10. A skier travels with a constant speed of 6 m s–1 along force F as shown. Work F x2 done by gravity till the a parabolic path y = . Find the acceleration of time, the chain leaves the 20 wedge will be the skier when he is at (10, 5). Neglect the size of the skier. ()31+ mgl ()32+ mgl − (a) (b) 9 92 2 2 (a) units (b) units 10 2 10 ()32+ mgl ()34+ mgl (c) − (d) (c) 1 units (d) None of these 4 4 10 PHYSICS FOR YOU | MAY ‘15 PAPER-1 SECTION-1 3. A voltmeter and an ammeter are joined in series to One or More Than One Options Correct Type an ideal cell, giving readings V and A respectively. This section contains 10 multiple choice questions. Each question If a resistance equal to resistance of ammeter is now has four choices (a), (b), (c) and (d) out of which ONE or MORE THAN joined parallel to ammeter then ONE are correct. (a) V will decrease slightly 1. A particle of mass m moves on the x-axis as follows: (b) V will increase slightly it starts from rest at t = 0 from the point x = 0, (c) A will become half of its initial value and comes to rest at t = 1 at the point x = 1. No (d) A will become slightly more than half of its other information is available about its motion initial value at intermediate times (0 < t < 1). If a denotes the 4. A charged particle goes undeflected in a region instantaneous acceleration of the particle, then containing electric and magnetic fields. It is possible (a) a cannot remain positive for all t in the interval that 0 ≤ t ≤ 1. (b) |a| cannot exceed 2 at any point in its path.
Load more

Recommended publications
  • Mass Transfer with the Marangoni Effect 87 7.1 Objectives
    TECHNISCHE UNIVERSITÄT MÜNCHEN Professur für Hydromechanik Numerical investigation of mass transfer at non-miscible interfaces including Marangoni force Tianshi Sun Vollständiger Abdruck der an der Ingenieurfakultät Bau Geo Umwelt der Technischen Universität Munchen zur Erlangung des akademischen Grades eines Doktor-Ingenieurs genehmigten Dissertation. Vorsitzender: Prof. Dr.-Ing. habil. F. Düddeck Prüfer der Dissertation: 1. Prof. Dr.-Ing. M. Manhart 2. Prof. Dr. J.G.M. Kuerten Die Dissertation wurde am 31. 08. 2018 bei der Technischen Universitat München eingereicht und durch die Ingenieurfakultat Bau Geo Umwelt am 11. 12. 2018 angenommen. Zusammenfassung Diese Studie untersucht den mehrphasigen Stofftransport einer nicht-wässrigen flüssigkeit ("Non-aqueous phase liquid", NAPL) im Porenmaßstab, einschließlich der Auswirkungen von Oberflachenspannungs und Marangoni-Kraften. Fur die Mehrphasensträmung wurde die Methode "Conservative Level Set" (CLS) implementiert, um die Grenzflache zu verfol­ gen, wahrend die Oberflachenspannungskraft mit der Methode "Sharp Surface Tension Force" (SSF) simuliert wird. Zur Messung des Kontaktwinkels zwischen der Oberflache der Flus- sigkeit und der Kontur der Kontaktflaäche wird ein auf der CLS-Methode basierendes Kon­ taktlinienmodell verwendet; das "Continuum Surface Force" (CSF)-Modell wird zur Model­ lierung des durch einen Konzentrationsgradienten induzierten Marangoni-Effekts verwendet; ein neues Stofftransfermodell, das einen Quellterm in der Konvektions-Diffusionsgleichungen verwendet, wird zur
    [Show full text]
  • ( 12 ) United States Patent
    US010177690B2 (12 ) United States Patent ( 10 ) Patent No. : US 10 , 177 ,690 B2 Boyd ( 45 ) Date of Patent: * Jan . 8 , 2019 ( 54 ) DEVICE AND METHOD TO GENERATE AND USPC .. .. .. 301/ 100 - 112 CAPTURE OF GRAVITO -MAGNETIC See application file for complete search history . ENERGY ( 56 ) References Cited (71 ) Applicant: Michael Boyd , Soquel , CA (US ) U . S . PATENT DOCUMENTS ( 72 ) Inventor: Michael Boyd , Soquel, CA (US ) 5 , 126 , 561 A 6 / 1992 Nakazawa 6 ,073 , 486 A 6 / 2000 Packard ( * ) Notice : Subject to any disclaimer , the term of this 6 ,359 ,433 B1 3 /2002 Hillis et al. patent is extended or adjusted under 35 6 ,956 ,707 B2 10 /2005 Ottesen et al. U . S . C . 154 ( b ) by 0 days. ( Continued ) This patent is subject to a terminal dis claimer . FOREIGN PATENT DOCUMENTS RU 2007119441 A 11 / 2008 (21 ) Appl . No. : 15 / 130 ,813 WO 2010010434 AL 1 /2010 ( 22 ) Filed : Apr . 15 , 2016 OTHER PUBLICATIONS (65 ) Prior Publication Data U . S . Appl. No. 12 / 159 ,657 , filed May 3 , 2011, Han et al . US 2017/ 0054389 A1 Feb . 23, 2017 (Continued ) Related U . S . Application Data Primary Examiner — Brandon S Cole (63 ) Continuation - in - part of application No . 13 /595 , 424 , (74 ) Attorney , Agent, or Firm — Patrick Reilly filed on Aug . 27 , 2012 , now Pat. No . 9 ,318 ,031 . (57 ) ABSTRACT A device and method of producing electrical energy by (51 ) Int . CI. gravitomagnetic induction utilizing Nano -features fabri G06T 7700 ( 2017 .01 ) cated on an object surface of an object is presented . The A631 33 / 26 ( 2006 .01 ) Nano - features may include Nano - bumps and Nano - pits .
    [Show full text]
  • List of Physical Properties in Chemistry
    List Of Physical Properties In Chemistry Blocked Garwin uncover irredeemably or suberizes massively when Matteo is lofty. Lemmie is scantier: she theologised closely and recrystallizes her tuner. Riddled Trevar enwinding very unqualifiedly while Piet remains bird-brained and ill-disposed. The melting point of an element or compound means the temperatures at which the solid form of the element or compound is at equilibrium with the liquid form. The property limits for oral bioavailability are well characterized. We all exhibit close similarity in basic structure and emotional makeup. The page was successfully unpublished. Steam condensing inside a cooking pot is a physical change, important information can be obtained about the purity of the material. Odor, publish and further license the Images. Aluminum oxide is a single, esp. An atom is the smallest unit of matter that retains all of the chemical properties of an element. For the elements, but even from most conventional heavy crude oils. It is currently providing data to other Web Parts, boiling point, such as structural markers on the molecule and partition coefficients. In each of these examples, or the reduced iron color persists in shades of green or blue. You picked a file with an unsupported extension. Since the water molecule is not linear and the oxygen atom has a higher electronegativity than hydrogen atoms, but the distinction has historically been made that way, a sort of submicroscopic billiard ball. The total atomic mass of an element is an equivalent of the mass units of its isotopes. So most historians agree that Scheele and Priestly should share credit for discovering oxygen.
    [Show full text]
  • EECS 598: Quantum Optoelectronics Instructor: Mack Kira ([email protected]) Term: Winter, 2020 Meeting Time: Tentatively Mo/We 12-1:30Pm, Room 3433 EECS
    EECS 598: Quantum Optoelectronics Instructor: Mack Kira ([email protected]) Term: Winter, 2020 Meeting time: Tentatively Mo/We 12-1:30pm, room 3433 EECS Ever wondered how the future of optics and electronics will look like, and which unexpected answers rational quantum engineering could deliver? If yes, you are ready to encounter the bizarre possibilities of the quantum realm – only enthusiasm and basic knowledge about quantum mechanics and electromagnetism is required! Optoelectronic devices are already being revolutionized by the prospects of quantum technology. Ever smaller and faster components will inevitably reach a level where a collective can outperform individual parts due to emergent quantum effects such as entanglement. This lecture welcomes you to the central concepts of quantum engineering of semiconductors to explore optoelectronic, quantum-optical, and many-body processes, relevant for state-of-the-art experiments and the future of quantum technology. Rough Syllabus: This lecture will provide a pragmatic and brief introduction to solid-state theory, many-body formalism, semiconductor quantum optics, and lightwave electronics to explore pragmatic possibilities for quantum technology. To develop your insights on rational quantum design, the coupling of the quantized light field to electrons is investigated in detail, while the Illustration of dropletons, measured many-body Coulomb interaction of charge carriers is and computed through quantum systematically included. For example, we will analyze (optical) spectroscopy. which quantum effects and quasiparticles can be used in optoelectronics devices from sensors to quasiparticle accelerators. To extend these quantum ideas further, we will follow how including quantum fluctuations of light to laser spectroscopy will transform it to quantum spectroscopy, a new realm where dropleton, entanglement, quantum memory etc.
    [Show full text]
  • Novel Nuclear Power Sources with Application to Space Propulsion
    id9429406 pdfMachine by Broadgun Software - a great PDF writer! - a great PDF creator! - http://www.pdfmachine.com http://www.broadgun.com Mehtapress 2015 Print - ISSN : 2319–9814 Journal of Online - ISSN : 2319–9822 SpFauclle pEapxerploration Full Paper WWW.MEHTAPRESS.COM Liviu Popa-Simil Novel nuclear power sources with application LAAS- Los Alamos Academy of Sci- to space propulsion ences, Los Alamos, NM 87544-0784 E-mail: [email protected] Abstract Received : March 13, 2015 Nuclear power is still a genuinely new domain with respect to space exploration. The field Accepted : April 27, 2015 is still in its infancy, despite of over 60 years of peaceful exploitation of nuclear power on Published : May 13, 2015 Earth, and many successful applications in space. Nuclear power sources are very compact and may be used for local power generation or as a source for propulsion in advanced thrusters. Fission batteries experience drastic limitations with respect to the energy that *Corresponding author’s Name & might be stored on board a spacecraft, due to criticality issues. Fusion batteries remove Add. this impediment, but fusion energy is in an early stage of technological research. Today, the best propulsion systems are inertial, jet based electric thrusters, providing a owerful Liviu Popa-Simil source of efficient propulsive energy, but even with the development of these thrusters, LAAS- Los Alamos Academy of Sci- travel throughout the solar system within reasonable time scales is unattainable. In the absence of other superior, physics-based propulsion concepts, nuclear-energy-powered jet ences, Los Alamos, NM 87544-0784 propulsion may take us to the limits of our solar system, but no further.
    [Show full text]
  • Quasiparticle
    CORE CONCEPTS CORE CONCEPTS Core Concepts: Quasiparticle Stephen Ornes Science Writer the material due to the long-range nature of the electromagnetic force, which adds up to one sprawling headache of a math prob- lem for condensed matter physicists who Physicists have identified dozens of differ- a lot of those: solids and liquids contain ent subatomic species in the particle zoo, on the order of 1024 particles per cubic want to study the properties of matter on but most physical and chemical interac- centimeter. the subatomic scale. The problem is partic- tions arise from only three: the proton, Each of those quantum mechanical par- ularly vexing for condensed matter phys- the neutron, and the electron. There are ticles may interact with all of the others in icists who study crystalline lattices or superconductors. Enter the quasiparticle, a mathematical con- struct that makes near-impossible calculations not only possible, but also straightforward. Decades ago, researchers realized that they don’t have to tackle the many-body problem that arises from the messy interactions of real quantum particles. Instead, a crystal solid can just as accurately be studied and analyzed as an averaged bulk object along with a collec- tion of quasiparticles: disturbances in the solid that act just like well-behaved, nonrel- ativistic particles that barely interact at all. They’re fictitious and easier to work with, and their collective behavior matches that of the real subatomic particles. An electron quasiparticle, for example, includes both the real electron and the nearby particles it affects—and may there- fore have a different mass.
    [Show full text]
  • Pair-Excitation Energetics of Highly Correlated Many-Body States 2
    Pair-excitation energetics of highly correlated many-body states M. Mootz, M. Kira, and S.W. Koch Department of Physics and Material Sciences Center, Philipps-University Marburg, Renthof 5, D-35032 Marburg, Germany E-mail: [email protected] Abstract. A microscopic approach is developed to determine the excitation energetics of highly correlated quasi-particles in optically excited semiconductors based entirely on a pair-correlation function input. For this purpose, the Wannier equation is generalized to compute the energy per excited electron–hole pair of a many-body state probed by a weak pair excitation. The scheme is verified for the degenerate Fermi gas and incoherent excitons. In a certain range of experimentally accessible parameters, a new stable quasi-particle state is predicted which consists of four to six electron– hole pairs forming a liquid droplet of fixed radius. The energetics and pair-correlation features of these ”quantum droplets” are analyzed. PACS numbers: 73.21.Fg,71.10.-w,71.35.-y arXiv:1307.7599v1 [cond-mat.mes-hall] 29 Jul 2013 Pair-excitation energetics of highly correlated many-body states 2 1. Introduction Interactions may bind matter excitations into new stable entities, quasi-particles, that typically have very different properties than the noninteracting constituents. In semiconductors, electrons in the conduction band and vacancies, i.e. holes, in the valence band attract each other via the Coulomb interaction [1]. Therefore, the Coulomb attraction may bind different numbers of electron–hole pairs into a multitude of quasi- particle configurations. The simplest example is an exciton [2, 3] which consists of a Coulomb-bound electron–hole pair and exhibits many analogies to the hydrogen atom [1].
    [Show full text]
  • Hyperbolic Bloch Equations: Atom-Cluster Kinetics of An
    Hyperbolic Bloch equations: atom-cluster kinetics of an interacting Bose gas M. Kira Department of Physics, Philipps-University Marburg, Renthof 5, D-35032 Marburg, Germany Abstract Experiments with ultracold Bose gases can already produce so strong atom–atom interactions that one can observe intriguing many-body dynamics between the Bose-Einstein condensate (BEC) and the normal component. The excitation picture is applied to uniquely express the many-body state uniquely in terms of correlated atom clusters within the normal component alone. Implicit notation formalism is developed to explicitly derive the quantum kinetics of all atom clusters. The clusters are shown to build up sequentially, from smaller to larger ones, which is utilized to nonperturbatively describe the interacting BEC with as few clusters as possi- ble. This yields the hyperbolicBloch equations (HBEs) that not only generalize the Hartree-Fock Bogoliubov approach but also are analogous to the semiconductor Bloch equations (SBEs). This connection is utilized to apply sophisticated many-body techniques of semiconductor quantum optics to BEC investigations. Here, the HBEs are implemented to determine how a strongly in- teracting Bose gas reacts to a fast switching from weak to strong interactions, often referred to as unitarity. The computations for 35Rb demonstrate that molecular states (dimers) depend on atom density, and that the many-body interactions create coherent transients on a 100 µs time scale converting BEC into normal state via quantum depletion. Keywords: Bose-Einstein condensate (BEC), Strong many-body interactions, Cluster-expansion approach, Semiconductors vs. BEC, Excitation-induced effects 1. Introduction Ultrafast spectroscopy[1, 2, 3, 4, 5, 6, 7, 8, 9, 10] is originally a concept of optics that is based on exciting and probing matter with laser pulses.
    [Show full text]
  • Plasma-Nano-Interface in Perspective: from Plasma-For-Nano to Nano- Plasmas
    This may be the author’s version of a work that was submitted/accepted for publication in the following source: Ostrikov, Ken (2019) Plasma-nano-interface in perspective: from plasma-for-nano to nano- plasmas. Plasma Physics and Controlled Fusion, 61(1), Article number: 0140281-6. This file was downloaded from: https://eprints.qut.edu.au/128586/ c Consult author(s) regarding copyright matters This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the docu- ment is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recog- nise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to [email protected] License: Creative Commons: Attribution-Noncommercial-No Derivative Works 4.0 Notice: Please note that this document may not be the Version of Record (i.e. published version) of the work. Author manuscript versions (as Sub- mitted for peer review or as Accepted for publication after peer review) can be identified by an absence of publisher branding and/or typeset appear- ance. If there is any doubt, please refer to the published source. https://doi.org/10.1088/1361-6587/aad770 Plasma-nano-interface in perspective: from plasma-for-nano to nano-plasmas.
    [Show full text]
  • Super-Capacitor-Like Structure for Fission-Fusion Direct Nuclear Energy Conversion L
    Super-capacitor-like Structure for Fission-Fusion Direct Nuclear Energy Conversion L. Popa-Simil* *LAAS, Los Alamos Academy of Sciences Los Alamos, NM 87544, USA, [email protected] ABSTRACT 2 NOVEL NUCLEAR POWER SOURCES One of the solution for future nuclear power sources Direct nuclear energy conversion system uses nano-hetero- rests in developments in nano-materials technology, that structures that harvest the nuclear particles energy, charging may facilitate direct nuclear energy conversion into electric a structure resembling a super-capacitor, that discharges energy, in compact supercapacitor-like solid-state devices, releasing it as electric energy. which rely on fission, fusion, or nuclear decay, being The nano-structure design uses heterogeneity, in order to generically called nuclear batteries. create a super-capacitor like structure, generically called “CIci”, where “C” is a conductive layer, made of a material with high electron availability, typically, but not limited to a high Z material, and “c” is a low electron availability material, simply a low Z material, or a combination of such. Specific insulators, also present as nano-layers, separate these two conductive layers. Constructive variants use nano-layers, nano-beads or nano- structures like nano-tubes or nano-wires, each having their particularities. The theoretical energy conversion is very high, but there are various constructive issues that limit the total conversion efficiency. This process determines the maximum power density a structure may provide. The use of the fission, fusion or mixed structures (hybrid Fig. 1 – The specific performances of prezent power rectors), provides energy on demand that is much better sources than the isotopic batteries, where these “CIci” structures The interest for the nuclear power sources is due to their might be successfully applied, but the energy depends on high energy/mass ratio, that is by three orders of magnitude the natural decay of the isotopes combination used.
    [Show full text]
  • Dream 2047, Science Reporter, Black Box in Aeroplanes Notes
    www.facebook.com/groups/abwf4india Facebook Group: Indian Administrative Service ( Raz Kr) RazKr [Live] - https://telegram.me/RazKrLive Notes 16 July 2015 20:07 Dream 2047, Science Reporter, Black box in aeroplanes Science Page 1 www.facebook.com/groups/abwf4india Facebook Group: Indian Administrative Service ( Raz Kr) RazKr [Live] - https://telegram.me/RazKrLive General science 13 September 2013 21:23 General Science NIOS, Std'10 Science TN, Imp points • According to Article 51a(h) of our Constitution, it is the fundamental duty of every citizen “to develop the scientific temper, humanism & the spirit of inquiry & reform” Electro magnetic waves 05-02-2015 Radio waves Radio waves are used for communication & broadcasting For eg. FM transmissions use the frequencies from 88MHz to 108 MHz, satellite communications use 4000-6000 MHz & 11000-14000 MHz generally & so on. Mobile service providers also use the radio waves normally in the range of 900-1800 MHz Spectrum allocation & auction • Two operators cannot use the same frequency in the same region as there will be interference btw each other & both the services will get affected • Same frequencies can be used at two different places separated by sufficient distance so that there will not be any interference. This is called space diversity • The number of voice channels that can be supported depends on the bandwidth of the frequency spectrum allocated. Higher the bandwidth, more the number of channels that can be accommodated • This radio frequency spectrum is a limited resource & different services are allocated different frequencies • So basically the users are allocated a band of radio frequencies for their service & this radio frequency band is called spectrum • The operators use these frequencies to provide service & earn revenue.
    [Show full text]
  • Linear Model for Diode;
    E L 7 6 D ELETRÔNICA APLICADA À ENGENHARIA MECÂNICA MICROELETRÔNICA: -Semicondutores; -Diodo Semicondutor. Aula 02 (10.mar.2020) MICROELETRÔNICA Dmitri Ivanovic MENDELEIEV (1834-1907) • CLASSIFICAÇÃO PERIÓDICA • SEMICONDUTORES • APLICAÇÃO NA ELETRÔNICA • ESTRUTURA CRISTALINA • PORTADORES DE CARGA • BANDAS DE ENERGIA • DOPAGEM MICROELETRÔNICA MICROELETRÔNICA Source: < https://www.coop.com.au/periodic-table-of-elements-reference-card-chm001/5555000095488 > MICROELETRÔNICA ELEMENTARY CONCEPTS • Atomic Models Philosophical → Democritus; Lavoiser; Dalton; Avogadro, Brown Subatomic particles → Thomson (“plum-pudding”), Rutherford; Bohr Quantum mechanics → Werner Heisenberg -19 • Elementary charge → qe = -1,6x10 [C] -31 • Electron mass → me = 9,1x10 [kg] • Electron radius → 10-15 [m] • Atom radius → 10-10 [m] MICROELETRÔNICA THE STRUCTURE OF MATTER - Dalton; - Thomson; - Rutherford-Bohr; - De Broglie (modelo quântico). MICROELETRÔNICA THE NATURE OF THE ATOM Dalton’s Atomic Theory Fonte: < https://www.youtube.com/watch?v=rxltY8HhQkA > DISCUSSIONS ABOUT DALTON´s ATOMIC THEORY • Innovatively: • Setbacks: MICROELETRÔNICA JOSEPH JOHN THOMSON´s ATOMIC THEORY Thomson's Model of an Atom - Class 9 Tutorial Fonte: < https://www.youtube.com/ watch?v=lLwnACfo7hY > DISCUSSIONS ABOUT THOMSON´s ATOMIC THEORY • Innovatively: • Setbacks: MICROELETRÔNICA ELECTRONIC STRUCTURE OF THE ELEMENTS (RUTHERFORD) Rutherford's Model of an Atom(US accent) Fonte: < https://www.youtube.com/watch?v=XLaeFUKd2Y4 > DISCUSSIONS ABOUT RUTHERFORD´s ATOMIC THEORY • Innovatively: •
    [Show full text]