The table below (figure 4) includes a comparison of dielectric strength values per the NEMA Standard Authorization Engineering Information for several common grades of rigid insulation material: Of course, these NEMA Standard values for dielectric strength are minimum values to meet that standard. The phenomenon of corona is generally accompanied by, In Van de Graaff generators output voltage is controlled by, Insulators for high voltage applications are tested for, Impulse testing of transformers is done to determine the ability Which of the following method or technique can be used for the (d) Boron nitride. D Less and cheap terminal equipments are required in HVDC. (b) working temperature Regions of high electrical stress can cause nearby gas to partially ionize and begin conducting. B. moisture content D.  It is highly inflammable. (c) intersheaths and insulating materials with different dielectric constants (d) Neel temperature. Webmicrosoft office professional plus 2016 product key 2022. prey 2022 123movies. (c) both permanent and induced dipoles. (c) Curie temperature. (a) armour Thickness of an insulating material plays a role in … (c) not easily machinable The thickness of insulation layer provided on the conductor, in cables, depends upon 13. The insulating material used for cables should have all of the following except A. High dielectric strength, high mechanical strength, high tensile strength and plasticity, high resistivity and high viscosity at impregnation temperature (b) porous (c) expand first and then rotate. If the point is now enclosed by a perfectly conducting sheet sphere at the point P. Outside the sphere, becomes 0 μVm 100 μVm -100 μVm 50 μVm Answer 19. (c) 3 only. (b) magnetic viscosity and hysteresis. (a) Stainless steel. A. heat conductivity (c) 3 and 4. Unilateral network Bilateral network Insulation Resistance should be high in insulators. Clarification: Insulation Resistance is very important in the performance of insulating materials. If the insulation resistance becomes low, high flow of current occurs and can damage the material. 6. How should the properties of strength and dielectric strength in insulating materials? on. A. Electro-mechanical breakdown of solid insulating materials occurs due to, 5. discharge can be observed as red luminescence. © 2003-2023 Chegg Inc. All rights reserved. finding online free courses with learning objective questions for any preparation. Electric strength in a cable is more on 10. Types of Lightning Arresters with Advantages and Disadvantages, Classification & Construction of all types of Electrical Cables, HVDC System Most Asked MCQS With Explanation, Cell And Battery Multiple Choice Questions and Answers-2021. (c) belted When the electric strength is increased beyond a particular value, it results in breakdown. -----24.B -----25.C ----- 26.C ----- 27.D -----28.D -----29.C ----- 30.C. The above statement is known as, Large capacity generators are manufactured to generate power at. (d) ferrimagnetic, (a) diamagnetic Temperature With increase in temperature, breakdown voltage reduces due to increase in thermal energy. (d) none of the above. B. dielectric strength All of the following dielectric materials are preferred for high (a) Ferromagnetic materials only. (c) time of application of the voltage. A. WebExplanation: The insulating materials should have less porosity as it should not lose the internal properties due to holes. (b) hardened and tempered A. maximum Van de Graaff generators are useful for, (A) Very high voltage and low current applications, (B) Very high voltage and high current applications, (C) Constant high voltage and current applications, 14. D. positive voltage conductor. WebSwitching surge is. © www.yourelectricalguide.com/ mcq questions on electrical cable. D. 50 kV, 27. Experts are tested by Chegg as specialists in their subject area. measurement of high ac voltages EXCEPT, The essential condition for the Paschen's law to be valid is that, The breakdown voltage in gases depends on, At unvarying temperature breakdown voltage in a uniform field is a This section is a repository of more than the multiple numbers of questions based on High Voltage Electrical Engineering. (e) both ferroelectric and piezoelectric. (c) Ferroelectric. They are easily molded, strong and resistant, and lightweight. (d) 2, 3 and 4. All students, freshers can download High Voltage Electrical Engineering You'll get a detailed solution from a subject matter expert that helps you learn core concepts. 230 V + 10 % with effect from 31 December 2009. Hyperbolic dying voltage. (a) 1 only. (d) can be used in high voltage circuits, (a) 0.04 mm C. 30 kV /mm C. both mechanical stress and electrical stress 33. (d) ageing and magnetic viscosity. Paramagnetic substances have very small positive values of susceptibility. (b) vulcanized rubber C. in panels for switchgear and arcing 42. (b) diamagnetic. The permeability of diamagnetic substances is slightly greater than unity. 23. WebElectrical breakdown occurs within a gas (or mixture of gases, such as air) when the dielectric strength of the gas (es) is exceeded. The dielectric strength is measured in kV. (b) 3 and 4. These mechanisms mainly include: • Thermal … They are easily molded, strong and resistant, and lightweight. Large capacity generators are manufactured to generate power at. C. pressed and varnished cloth (c) ferromagnetic (c) hysteresis, leakage and copper losses only WebThe electric breakdown strength of insulating materials depends on a variety of parameters, such as pressure, temperature, humidity, field configurations, nature of applied voltage, imperfections in dielectric materials, material of electrodes, and surface conditions of electrodes, etc. incorrect ? Which of the following is a polar dielectric ? 10kV Select the correct answer using the codes given below 17.B ----- 18.C ----- 19.B ----- 20.D ----- 21.B ----- 22.D ----- 23.C Loss Tangent or tan δ is a dimensionless quantity. (d) all of the above. 10 wires O c. 4 wires O d. 8 wires. (d) Compressed SF6 gas You don't need to login to post your comment. (b) grading according to capacitance of cables per km length B. reducing the breakdown strength, is, 7. B. Steatite 20 kV WebPolyamide resins contain an amide group as a recurring part of their molecular chains. Hyperbolic dying voltage. (c) the capacitances of insulated conductors (a) hard dielectrics. 09, 2018 • 16 likes • 11,335 views Download Now Download to read offline Engineering High Voltage Engineering (Electrical Engineering) MUET SZAB Campus Khairpur Mir's Sindh Pakistan Follow Advertisement Recommended Dielectrics parth98796 8.2k views • 32 slides … III. WebBreakdown Voltage Test or Di-electric Strength Test of Insulating Oil. It tends to depend mainly on the Dielectric material and the frequency. In simple terms, dielectric strength is the ability of an insulating material to withstand applied electrical stress. Insulation used in commutator is (d) none of the above. (a) 1, 2 and 3 only. High voltage dc. (a) diamagnetic. For More Quizzes Visit: “ Electrical Ride Quizzes.”. (d) hygroscopic. (b) bedding (a) 5 ohms We have also provided the answers to all the High Voltage Electrical Engineering Questions. (b) ferromagnetic A. High dielectric strength, high mechanical strength, high tensile strength and plasticity, high … (c) Curie 10. (d) 4 alone. We will update the questions related to the High Voltage Electrical Engineering on this page. Select the correct answer using the codes given below: B. for equipment working at high temperature … 5 Ratings (18 Votes) D. All the above. Dielectric Loss is measured using the Loss of tangent which is also commonly referred to as tan delta (tan δ). (a) negative (d) polar, (a) critical Solid type cables are considered unreliable beyond 66 kV because. As per IE Rule, In the case of low or medium voltage, As per IS 12640:1988, Supply variation will become. (b) leads the voltage by 90oC In this example then the test voltage of 11,180 V can be used since it is less than the breakdown voltage of the … In 1955, the dielectric strength of insulation materials and its relation with the electric field strength between high voltage and ground electrodes were studied. (b) 15 kV/mm 1500 kV/mm As compared to air the relative dielectric strength of sulphur (a) steel tape Value). B It has high capacitance hexafluoride is nearly, The electrical breakdown strength of insulating materials depends The NEMA Standard for GPO-3 requires a 40 kV value and the TGC material tested at 50 kV. Parallel pin electrodes were used in oil. Paper This voltage disturbs the electric as well as mechanical properties of the material. Most manufacturers far exceed the minimum standard, as evidenced in the table showing dielectric strength properties for NEMA GPO-3 (Figure 3). (A) a - (i), b - (ii), c - (iii), d - (iv), (B) a - (ii), b - (i), c - (iv), d - (iii), (C) a - (iv), b - (i), c - (ii), d - (iii). (a) only expand. Vacuum insulation is used in all of the following EXCEPT, 25. However when a large enough electric field is applied to any insulating substance, at a certain field strength the concentration of charge carriers in the material suddenly increases by many orders of magnitude, so its resistance drops and it becomes a conductor. This is called electrical breakdown. (D) electrical stresses produced by the voltage fluctuations. The electric breakdown strength of insulating materials depends on A Nature of applied voltage B Imperfection of dielectric material C Pressure, temperature … The breakdown voltage in gases depends on, 39. WebSelection of material for use in edible packaging is based on its properties to act as barrier to moisture and gases, mechanical strength, physical properties, and resistance to microbial growth. Evidence of strong correlation between space-charge buildup and breakdown in cable insulation. In the state space model of a dynamic system with matrices A, B, C and D, what is the matrix A also called? (a) oil filled (b) Rochelle salt. (b) low cost (c) provide proper insulation In addition, The Gund Company offers materials engineering presentations and training seminars for our customers to help them understand a wide range of modern material properties and capabilities. (a) 1 and 4. (c) ferromagnetic substance. C It is an organic material of, Transformers contribute to radio interference due to, As compared to air the relative dielectric strength of sulphur Solved examples with detailed answer description, explanation are given and it would be easy to understand. (a) Joule’s temperature. type Yewen Zhang. (b) to avoid being unearthed easily due to removal of soil (d) hard, brittle and not easily machinable. C. mechanical strength The magnetization is entirely solenoidal and divergent. incorrect ? Learn more. Multiple Choice Answer: C Use of HVDC can improve system stability, (I) To regulate interstate transmission of electricity, (II) Promotion of investment in electricity industry, (111) To determine tariff for interstate electricity transmission, A generating station to a switching station/stepdown transformer station, B stepdwon transformer station to service transformer banks, C distribution transformer to consumer peremises, Answer: A generating station to a switching station/stepdown transformer station. (e) none of the above. (a) annealed (c) conductor surface (A) Corona gives Such transient … Web22. Pressure cables are generally used beyond 11. Ltd. Design & Developed by:Total IT Software Solutions Pvt. (d) none of the above. (a) presence Direct transmission matrix. (d) none of the above. 41. In this example then the test voltage of 11,180 V can be used since it is less than the breakdown voltage of the … Which variety of mica is hard and brittle ? (c) between 8 and 10 (b) between 5 and 6 (c) either of the above Webmicrosoft office professional plus 2016 product key 2022. prey 2022 123movies. WebElectric strength of solid insulation under ac stress depends on time of exposure at a given stress level. Questions and Answers as PDF files and eBooks. (c) to minimize the effect of shocks and vibration, duo to passing vehicles etc. How do you calculate dielectric breakdown voltage? 250+ TOP MCQs … (c) maximum at the conductor and minimum at the sheath ----- 39.C ----- 40.B -----41.D ----- 42.B -----43.D -----44.B ----- 45.C, “  Nerathai venakkum (b) Ferromagnetism. The electrical breakdown strength of insulating materials depends on: a. imperfections in dielectric material O b. nature of applied voltage O c. pressure, temperature and humidity O d. all of the above. (c) Ferroelectric characteristic only above the Curie point. The surface modification of nanoparticles (NPs) is crucial for fabricating polymer nanocomposites (NCs) with high dielectric permittivity. (d) hysteresis loop area for the material. In sphere gaps, the sphere are made of. (b) insulators. (a) composite poothu kadikarathai paar ootuvathu mull alla uun vaalkkai “, Dielectric strength in case of mica can be expected to be more C.  It is non-toxic. The insulator should have (c) homogeneous (b) equal to This is called creepage failure. Which of the following technique/method is-used for the B. proportional to applied voltage. D. none of above, 25. So, you need to check all the questions in the High Voltage Electrical Engineering MCQ Quiz to prepare for the exams. (b) positive REACH RoHS High voltage ac. D. all of the above, 14. Most commonly, the test voltage is applied using simple test electrodes on opposite faces of specimens. than, 2. C. Fibiolite If your company would like to compare the dielectric properties of two or more materials under consideration for a particular application design, our complete testing lab can offer some insight into material performance for your review. Test results are expressed in total voltage (usually kV)required to cause a breakdown, so the thickness tested is critical. (d) spontaneous magnetization. (c) Piezoelectricity. function of the product of gas pressure and distance between the electrodes. In solenoid magnetization is due to a surface current distribution. (c) high melting point. Impulse testing of transformers is done to determine the ability (D) Corona is always accompanied by a hissing noise. The thickness of the layer of insulation on the conductor, in cables, … (b) jute WebThe power dissipated in a pure capacitor is. Magnetization has its origin in circulating current. 7. D.  negligible, 11. (c) two Your email address will not be published. B. crystalline structure D. low relative permittivity, 24. A It is hygroscopic 103 to 1017 ohm-m The electrical breakdown strength of insulating materials depends on, 9. (a) insulation layer 3. Nelson (1981) reports the results … vibrations. The dielectric strength of ferroelectric materials depends to a large extent on (a) frequency of applied voltage. (b) diamagnetic (c) presence of magnetic materials in the vicinity. (c) 15 kV/mm A.  MgO (c) impregnated paper (b) Super tension The breakdown mechanism probably varies with time. Outstanding design services at affordable price without compromising on quality, Helps You to establish a market presence, or to enhance an existing market position, by providing a cheaper and more efficient ecommerce website, Our quality-driven web development approach arrange for all the practices at the time of design & development, Leverage the power of open source software's with our expertise. (b) high Curie temperature. mechanical stresses produced by the electrical … (d) leads the voltage by 180oC. Vacuum insulation is used in all of the following EXCEPT. (a) eddy currents and magnetic viscosity. D. Glass, 20.Which of the following is a ceramic material? A. polyvinyl chloride D.  Wooden Insulation, 23. due to, (C) mechanical stresses produced by the electrical field. (A) Insulation may melt due to higher temperature. (D) a - (iii), b - (iv), c - (i), d - (ii). WebLearn Electrical Cables MCQ questions & answers are available for a Electrical Engineering students to clear GATE exams, various technical interview, competitive examination, and another entrance exam. (d) very high. (b) bedding > Multiple Choice Questions of High Voltage Engineering (01-15): 1. WebTable 1 – Properties of typical insulation materials 4. Which variety of mica is hard and brittle ? 5. 8. General ONLINE MCQ EE. (d) none of the above. Review With a high enough applied voltage, electrons can be freed from the atoms of insulating materials, resulting in current through that material. (d) resistors. C.  Invar (b) minimum at the conductor and maximum at the sheath WebAnswer: Option A. Q 7. (c) 3 to 5 mm Line insulators are made of Temperature : The insulation resistance decreases with temperature. (d) none of the above. Ans: a. WebClarification: Mica has one of the highest dielectric strengths of 100 X 106 V/m. Which of the above statements is/are correct? D. positive and dependent of temperature, 16. 6. In the state space model of a dynamic system with matrices A, B, C and D, what is the matrix A also called? (c) provide proper stress distribution Electro-mechanical breakdown of solid insulating materials occurs (b) Faraday temperature. 1 Approved Answer. b. Here, we systematically studied the effect of surface functionalization of TiO2 and BaTiO3 NPs to enhance the dielectric permittivity of polyvinylidene fluoride (PVDF) NCs by 23 and 74%, respectively, … The higher the value of tan delta is, the more the Dielectric Loss is likely to be. 500 kV/mm As compared to air the relative dielectric strength of sulphur hexafluoride is nearly (A) 1.5 times (B) 2.5 times (C) 4.0 times (D) 5.0 times. (d) hysteresis, leakage, copper and friction losses. WebEngineering Physics Questions and Answers – Dielectric Breakdown « Prev Next » This set of Engineering Physics Multiple Choice Questions & Answers (MCQs) focuses on … If the insulation thickness is sufficiently great, failure can occur across the surface of the insulation. ----- 2.B ----- 3.C ----- 4.C ----- 5.A ----- 6.C ----- 7.D ----- 8.C -----9.C 200. Web03․. At the breakdown, the electric field frees bound electrons. (c) cables using single dielectric in different concentrations Which of the following method or technique can be used for the (a) avoid excessive sheath losses (d) Electric dipole moment. However, once the matrix begins to break down thermally around 700 hours, the dielectric strength also drops dramatically. (c) absence of ripples Three-phase Induction motor Shunt motor Synchronous motor Differential compound motor Show Answer Workspace 2) Which of the given networks are based on the compensation theorem? WebThe field strength at which break down occurs depends on the respective geometries of the dielectric (insulator) and the electrodes with which the electric field is applied, as well as … School U.E.T Taxila; Course Title EE 1452; Type. Which soil has the maximum specific resistance ? Which soil has the maximum specific resistance ? (b) Brass. We offer an extensive range of e-commerce website design and e-commerce web development solutions in the form of e-commerce payment gateway integration, shopping cart software, custom application development, Internet marketing, e-Payment to companies across the globe. (c) high dielectric strength Polar dielectrics are normally used for. The disadvantage with paper as an insulating material is We can create a custom cross-platform; web-based one build for every device solution. Copper as conductor for cables is used as (A) Annealed (B) Hardened and tempered (C) Hard drawn (D) Alloy with chromium (c) ferromagnetic Jan 1997. (a) to minimize temperature stresses D. insulation for traction motors and auto mobile starting motor, 2. (c) Both 1 and 2. (a) large saturation magnetization. ---------------- class of ceramics is used for high frequency applications. A. These properties should limit some short-term breakdown mechanisms, distinguished in three main types: (i) Electrical breakdown: this is a very fast mechanism which is not preceded by any increase of the … B. post varnish conductor B. (d) capacitance required to be introduced at different lengths to counter the effect of inductance (a) hysteresis losses only D. Titanite, 4. What is key Difference between Onload tap changer and Off load tap changer ? Which variety of mica is hard and brittle? If the applied electric field is sufficiently high, free electrons may become accelerated to velocities that can liberate additional electrons during collisions with neutral atoms or molecules in a process called avalanche breakdown. Which of the following gas has been used as insulating medium in (b) avoid the requirement of good insulation WebQuestion: The electrical breakdown strength of insulating materials depends on: a. imperfections in dielectric material O b. nature of applied voltage O c. pressure, … (c) Lead zirconate. The voltage corresponding to dielectric strength is called breakdown voltage and is expressed in kV/mm. (a) ferroelectric. Notes. (a) Magnetostriction. B. Porcelain The materials have negative magnetic susceptibility. (c) Armouring Electrical Cables MCQ question is the important chapter for a Electrical Engineering and GATE students. 4. A.  Mica © 2022 Copyright: C. Asbestos (c) slightly more than State the factors on which life of Insulation depends. (d) ferrimagnetic. (d) 1, 2, 3 and 4. (c) Impregnated paper Required fields are marked *. In Van de Graaff generators output voltage is controlled by, (A) controlling the corona source voltage, 1.A All of the following methods/techniques can be used for the D. all of the above, 29.The thickness of the layer of insulation on the conductor, in cables, depends upon Which of the following is a non-polar dielectric ? (b) spontaneous Continuous Improvement, Copyright © 2021 The Gund Company, Inc. All Rights Reserved, Protek Frac Balls – Proven Performance Under Pressure, Dielectric Strength Perpendicular in Oil (.0625”), Breakdown VoltageParallel Pin in Oil (.0625”). WebElectrical MCQs 1) Which of the given motor has insufficient starting torque at full load speed with the same H.P. (d) none of the above. 28. (a) paramagnetic substance. In a sufficiently strong electric field the insulating properties of an … Electro-mechanical breakdown of solid insulating materials occurs due to. We will provide you the secure enterprise solutions with integrated backend systems. Calculate the breakdown strength of air, if gap between two spheres is 10 mm and the breakdown voltage is 20 kV(R.M.S. (a) PVC Dielectric strength is the measure of the ability of an insulating material to withstand an … The below list provides all the multiple-choice questions related to engineering materials. results in loss of power in transmission, (C) Corona ONLINE Multiple Choice Questions – Electric Machine Design PART 4 . View. At unvarying temperature breakdown voltage in a uniform field is a (b) ferrimagnetic Having reliable, timely support is essential for uninterrupted business operations. 13.The electric breakdown strength of an insulating material depends on A. composition of material B. moisture content C. thickness of material D. all of the …

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