(d) none of the above In a cable, the maximum stress under operating conditions is at Electrical breakdown or dielectric breakdown is a process that occurs when an electrical insulating material, subjected to a high enough voltage, suddenly becomes an electrical conductor and electric current flows through it. If a cable of homogeneous insulation has a maximum stress of 10 (b) No Electrical Cable MCQ . (a) low cost In cables the charging current (b) jute a) The saturation voltage VCF of silicon transistor is more than germanium transistor. The breakdown voltage of a cable depends on (a) presence of moisture (b) working temperature (c) time of application of the voltage (d) all of the above Ans: d. 51. The electric breakdown strength of a gas-insulated gap between two metal electrodes can be improved considerably when one or both of the electrodes are covered with a dielectric coating. (d) none of the above « Back CONTENTS Next » 1. minimum distance between the two, to avoid interference, should be (a) 5 kV/mm by the use of (d) all of the above (a) blue (a) Yes Ans: d, 51. ASWDC (App, Software & Website Development Center) Darshan Institute of Engineering & Technology (DIET) a. Additional desirable properties of insulating material depend on the type of applications. Before selecting an insulation system for a particular application, the following properties need to be considered. Dielectric Strength reflects the electric strength of insulating materials at various power frequencies. Properties of Ceramics 1.3. Dielectric breakdown voltage is determined by: (d) none of the above Ans: a, 13. (6) it has high capacitance (b) 33kV ii)Medium resistances – Resistances ranging from about 1 ohm upwards to about 100000 ohms. (c) belted A certain cable has an insulation of relative permittivity 4. (c) the capacitances of insulated conductors (d) armoured (a) hysteresis losses only (e) none of the above b. The thickness of the layer of insulation on the conductor, in cables, In capacitance grading a homogeneous dielectric is used. (a) 11kV Ans: c, 36. An insulating material must have high resistivity and high dielectric strength. (d) 100 ohms (b) hardened and tempered It is an indicator of … Parameters of Transformer Oil 1.7. iii). (a) prevent the moisture from entering the cable (b) non-existence of any stability limit Ans: c, 22. (a) between 2 and 3 (a) High tension (c) 50 cm (a) presence of moisture Ans : Temperature Coefficient of resistance is defined as the change in resistance per degree change of temperature per ohm of resistance. ‘draw in system’ of laying of underground cables The disadvantage with paper as insulating material is (a) it is hygroscopic (6) it has high capacitance (c) it is an organic material (d) none of the above Ans: a. (b) make it flexible your ... Leave a Comment / Uncategorized / By Ajay Sharma. (d) for all of the above reasons Multiple Choice Question (MCQ) of Electronics page-15:211. (a) 5 ohms Solved examples with detailed answer description, explanation are given and it would be easy to understand. The material for armouring on cable is usually (b) No In cables the charging current (a) lags the voltage by 90° (b) leads the voltage by 90° (c) lags the voltage by 180° (d) leads the voltage by 180° 2. Ans: b, 30. d) None of the above, Multiple Choice Question (MCQ) of Electronics page-13:181. (a) Bedding (d) none of the above Ans: d, 2. Applications of insulating materials - Electrical Engineering (MCQ) questions and answers. Ans: c, 3. In physics, the term dielectric strength has the following meanings: for a pure electrically insulating material, the maximum electric field that the material can withstand under ideal conditions without undergoing electrical breakdown and becoming electrically conductive. (a) Polyvinyle chloride (b) working temperature (c) lags the voltage by 180° Ans : A semiconductor is a substance whose resistivity lies in between those of good conductor and insulator. (b) minimum at the conductor and maximum at the sheath ... Moisture will reduce the dielectric strength of the oil and hence insulation is weakened. The intersheaths in the cables are used to (a) oil filled Which of the following protects a cable against mechanical injury ? 34 The electric breakdown strength of insulating materials depends on 35 The from EET 130 at ECPI University (b) Vulcanised rubber (d) Extra super voltage Save my name, email, and website in this browser for the next time I comment. Multiple Choice Question (MCQ) of Electronics page-16:226. So the type of insulating material used in a cable depends upon the service for which the cable is required. the cable will become Ans: a, 15. The dielectric strength is a very essential parameter for designing the insulation system, especially for high voltage applications. d) Inner and bound electrons are always present in the semiconductor. Ans: c, 24. This page contains the High Voltage Electrical Engineering MCQ Quiz related to the multiple choice questions. Ans: c, 10. For a specific piece of dielectric material and location of electrodes, the minimum applied electric field that results in … (a) Yes In capacitance grading of cables we use a ______ dielectric. Ans: c, 7. i) Low resistivity, If a power cable and a communication cable are to run parallel the Ans: b. The electrostatic stress in underground cables is Natural rubber is obtained from milky sap of tropical trees. Basic Electrical Engineering MCQ_43(Engineering Materials) byelectricalworld February 10, 2019. (d) None of the above insulation is replaced by one of relative permittivity 2, the capacitance of b) CUJT Ans: a, 50. ... The disadvantage with paper as insulating material is (a) it is hygroscopic (6) it has high capacitance (c) it is an organic material (d) none of the above . (a) insulation may melt due to higher temperature d) Alloys, Multiple Choice Question (MCQ) of Electronics page-14:196. (a) Yes Ans : From the point of measurement resistances are classified as follows :- The first and foremost factor is the material which makes the insulator. (b) 10 cm (c) ... Natural mineral oil used in the transformer. Ans: c, 44. (c) brown (a) 200 V (a) lags the voltage by 90° Ans: a, 47. it will not absorb moisture. (b) No Operating voltage. (d) positive voltage conductor (a) Yes (e) none of the above vi) High ductility. (a) insulation layer Underground cables are laid at sufficient depth Ans : A good insulator must have the following properties :-. (b) Sheath Which of the following statement is true? (c) between 8 and 10 would you prefer ? 1. PVC stands for Ans: a, 51. (e) none of the above Ans : Resistance ∝ Length/(Area of cross section) Ans: c, 6. (b) becomes one-half (d) all of the above (function() {var script=document.createElement("script");script.type="text/javascript";script.async =true;script.src="//telegram.im/widget-button/[email protected]";document.getElementsByTagName("head")[0].appendChild(script);})(); The insulation of the cable decreases with The disadvantage with paper as insulating material is (a) it is hygroscopic (6) it has high capacitance (c) it is an organic material (d) none of the above Ans: a. In the cables, sheaths are used to (a) prevent the moisture from entering the cable (b) provide enough […] Dielectric strength of a material depends on a) moisture content b) temperature c) thickness d) all of the above (c) homogeneous (c) either of the above Which of the following statement is correct? Ans : Germanium (Ge), Silicon (Si), Selenium (Se), Carbon (C) etc. Skip to content. Ans: c, 46. (a) avoid excessive sheath losses Ans: d, 12. (d) 40 to 60 mm The electric breakdown strength of insulating materials depends on (A) Nature of applied voltage (B) lmperfection of dielectric material (C) Pressure, temperature and humidity nature and composition of conductor material, (4) Temperature and (5) Nature of the current flowing through the conductor. The thickness of insulation provided on the conductor in the cable depends on which among the following factor? The insulating material for a cable should have (d) leads the voltage by 180° (d) there is a danger of breakdown of insulation due to the presence of voids (b) 33 kV (a) it is hygroscopic Contents hide 1. A cable carrying alternating current has (b) low cost (c) hysteresis, leakage and copper losses only Ans: c, 20. Rubber is most commonly used insulation in cables. (a) unsheathed cables (b) the inductance of conductors (c) no ionisation, oxidation and formation of voids e) Holes and electrons simultaneously, Basic Electrical interview Questions & Answers paper-4, Basic Electrical interview Questions & Answers paper-3, Basic Electrical interview Questions & Answers paper-2, Basic Electrical interview Questions & Answers paper-1. Some of the typical Electrical properties of engineering… (b) smaller overall size (b) 20 ohms The disadvantage with paper as insulating material is Types of insulating materials 1.1. i). www.gtu-mcq.com is an online portal for the preparation of the MCQ test of Degree and Diploma Engineering Students of the Gujarat Technological University Exam. (c) Insulating materials for transformers. Home >> Category >> Electrical Engineering (MCQ) questions and answers >> Applications of insulating materials; 1) The temperature limit for class F insulation is. A.C. mainly due to (b) Super tension The voltage at which a given insulating object becomes conductive is called its breakdown voltage and depends … (d) rubber insulated (a) annealed (d) none of the above The electric breakdown strength of insulating materials depends on. Ans: a, 11 cables are used for 132 kV lines. Copper as conductor for cables is used as Because different materials have different dielectric strength. High Voltage Breakdown Measurement Dielectric breakdown is the failure of an insulating material to prevent the flow of current under an applied electrical stress. Ans: a, 53. b) The saturation voltage VCE for germanium transistor is more than silicon transistor. Ans : Resistance is increased with the rise in temperature end decreased when cooled. The surge resistance of cable is d) The saturation voltage VCE for silicon transistor is lower than germanium transistor. The insulation resistance is also increased by glazing. (b) high resistivity Ans: d, 18. The bedding on a cable consists of type 0 answers. The insulating material for cables should Ans : Resistance is the property of a substance which opposes the flow of electricity through it. mcq questions on electrical cable. (a) the increase in length of the insulation Electrical breakdown is often associated with the failure of solid or liquid insulating materials used inside high voltage transformers or capacitors in the electricity distribution grid. (c) four times i) Intrinsic semiconductors in pure form and (c) high mechanical strength (b) No All insulating materials undergo breakdown when the electric field caused by an applied voltage exceeds the material's dielectric strength. (c) impregnated paper When the electric strength is increased beyond a particular value, it results in breakdown. (d) remains unchanged Conduit pipes are normally used to protect _____ cables. (c) pressed and varnished cloth Ans : There are two types of semiconductors : Low tension cables are generally used up to (d) 400 cm (a) use of dielectrics of different permeabilities Electrical insulating material can be defined as a material that does not allow electric current to pass through it. (d) 1000 V (c) 66 kV (b) 0.2 to 0.4 mm The dielectric strength of ferromagnetic materials depends to a large extent on. (a) easy maintenance (c) maximum at the conductor and minimum at the sheath (b) vulcanised rubber (c) provide proper stress distribution (d) none of the above It is difficult to maintain oil filled cables. (a) Yes etc. a) Majority carriers aluminium. (a) same at the conductor and the sheath ii) Less variation in resistance with temperature, (a) sheath Extrinsic semiconductors are sub divided into two types depending upon the type of impurity added such as (1)N-type and (2) P-type. d. Both (a) and (b). depends upon Its resistance decreases with rising temperature and the presence of impurities in contrast to the normal metallic conductor for which normally behaves like an insulator. Ans : Semiconductors are generally used in electronic devices such as Radio, Television I.C.,V.C.R. (c) of corona loss between conductor and sheath material Ans: a, 31. Synthetic insulating fluids used in the transformer. (b) galvanised steel wire (d) all of the above If the (e) none of the above (b) No (c) smaller dielectric loss Multiple Choice Question (MCQ) of Electronics page-14:196. Solid type cables are considered unreliable beyond 66 kV because Ans: a, 40. ii)Extrinsic semiconductors with added impurities. The dielectric strength of a material depends on the specimen thickness (as a rule, ... kinds of electric breakdown are thermal and electrical breakdowns. Ans: c, 35. (adsbygoogle = window.adsbygoogle || []).push({}); Ans : Resistor or Rheostat is a device whose chief property is to oppose or resist the flow of electricity. (b) insulating materials with different dielectric constants The current carrying capacity of cables in D.C. is more thanthat in (a) reactive power (a) armour Ans: d, 49. (c) Paper Ans: d, 8. (a) becomes one-fourth (c) becomes double (c) Armouring (d) conductor surface (a) one half (d) all of the above b) Bound electrons are always present in the semiconductor. In congested areas where excavation is expensive and inconvenient (a) polyvinyl chloride DIELECTRIC STRENGTH OF INSULATING MATERIALS L. I. Berger The loss of the dielectric properties by a sample of a gaseous, ... (or breakdown voltage). (c) compressed oil or compressed gas insulated (b) No Ans: b, 38. (a) inter-sheaths (c) any of the above Ans: d, 28. (d) Compressed SFe gas Non-hygroscopic i.e. The materials whose electrical conductivity is usually less than 1 × 10 6 mho/m are a) Semiconductors b) Conductors c) Insulators. The metallic sheath may be made of lead or lead alloy or of (c) both (a) and (b) The disadvantage with paper as insulating material is (a) it is hygroscopic (6) it has high capacitance (c) it is an organic material (d) none of the above Ans: a 50. (b) provide enough strength (a) minimize the stress In a cable the voltage stress is maximum at (d) Insulating materials … mcq questions on electrical cable. (e) surface of the conductor Resistance varies, directly proportional to the length and inversely proportional to the cross section. Ans: d, 17. Insulating material used for manufacturing insulated cables/wires must be flexible such as rubber or PVC. Ans: a, 5. Ans: d, 48. Ans: a, 54. To finalize the material for an engineering product / application, we should have the knowledge of Electrical properties of materials. (b) S.L. 50. (c) Impregnated paper (a) varnished cambric (c) 50 ohms (c) either (a) or (b) (d) none of the above Or it can be defined as the measure of dielectric breakdown resistance of a material under an applied voltage and is expressed as Volts per unit thickness. (b) grading according to capacitance of cables per km length (b) bedding 120°C c. 130°C d. 155°C. Dielectric strength of rubber is around (b) be non-inflammable Insulation & Insulating materials - MCQs with Answers Q1. (a) be acid proof Ans: b, 32. i)Low resistances – All resistances of the order of 1 ohm or less. (d) alloy with chromium etc. iii)High resistances – Resistances of 100000 ohms and above. Ans: a, 59. Ans: a, 23. (d) hysteresis, leakage, copper and friction losses (d) can be used in high voltage circuits c) PUT Multiple Choice Question (MCQ) of Electronics page-17:241. (c) armour (a) low permittivity (a) hessian cloth Ans: a, 43. (d) none of the above (b) post varnish conductor (e) 3 to 5 mm (b) between 5 and 6 (e) none of the above Ans: c, 41. Ans: c, 25. The conduction in JEFT is always by the Ans: d, 14. (a) composite (c) to minimise the effect of shocks and vibrations due to gassing vehicles, 1 Answer to The electrical breakdown strength of insulating materials depends on (A) nature of applied voltage (B) imperfections in dielectric material (C) pressure, temperature and humidity (D) all of … The electrical breakdown strength of insulating oil depends on the size of foreign particles which may form bridges in a place of maximum electric stress. 49. The breakdown of insulation of the cable can be avoided economically b) Conductors 50. (b) No (e) none of the above Ans : A good conductor must have the following properties :- (d) have all above properties (a) the resistance of the conductor MCQ of Electrical Machines page-5. 105°C b. Pressure cables are generally not used beyond (b) bedding In single core cables armouring is not done to The minimum dielectric stress in a cable is at effect of inductance (c) high dielectric strength The dielectric strength of an insulating medium depends on many factors. (d) all of the above In a cable immediately above metallic sheath _____ is provided. Ans: b, 9. Dielectric strength is an intrinsic material property that represents the maximum electric field a pure material is able to sustain ideally before its insulating properties begin to fail. (a) Yes c) Holes The breakdown voltage of a cable depends on (a) presence of moisture (b) working temperature (c) time of application of the voltage (d) all of the above Ans: d. 51. The electrical breakdown strength of insulating materials depends on A. nature of applied voltage; In the cables, sheaths are used to (c) be non-hygroscopic Capacitance grading of cable implies (b) high dielectric strength 16 The electrical breakdown strength of insulating materials depends on A : nature of applied voltage B : imperfections in dielectric material C : pressure, temperature and humidity D all of the above: 17 Which of the following gas has been used as insulating medium in electrical appliances ? We respect your privacy and take protecting it seriously, Click to share on Facebook (Opens in new window), Click to share on Telegram (Opens in new window), Click to share on WhatsApp (Opens in new window), Click to share on LinkedIn (Opens in new window), Click to share on Reddit (Opens in new window), Click to share on Tumblr (Opens in new window), Click to share on Pinterest (Opens in new window), Click to share on Pocket (Opens in new window), Click to share on Skype (Opens in new window), ELECTRONICS AND COMMUNICATION ENGINEERING IMPORTANT MCQ-DIGITAL ELECTRONICS, FREE EE ONLINE TEST-A.C. FUNDAMENTALS,CIRCUITS AND CIRCUIT THEORY PART 2, ONLINE MCQ EE AND ECE-A.C. Ans : Insulator resistance of most solid dielectric with the possible exception of mica and asbestos is decreased with the rise in temperature and increased when cooled. Subscribe to our mailing list and get interesting stuff and updates to your email inbox. c) Free electrons are always present in the semiconductor. Transformer Oil 1.6. asked May 8, 2018 in Electric Power Transmission by Q&A. The advantage of cables over overhead transmission lines is The thickness of metallic shielding on cables is usually (a) to minimise temperature stresses a. (6) double (b) avoid the requirement of good insulation (d) none of the above All Exam Review. (c) armouring (d) none of the above (d) all above parameters (b) 500 V Ans : The specific resistance or resistivity of a conductor is the resistance offered by unit metre cube of the material of that conductor. Ans: d, 45. (a) 15 kV/mm (c) any of the above This theoretical relation was verified with colloid suspensions of particles of known radius. c) The saturation voltage VCE for silicon transistor is same as that for germanium. Ans: c, 29. (d) 132 kV Ans : Resistance of a conductor depends on its (1)Length, (2)Cross section, (3) Resistivity i.e. Ans: a, 26. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are (d) 132 kV 1 Dielectric constant for vacuum is___. (e) provide proper insulation (c) hard drawn c) Insulators kV/mm, then the dielectric strength of insulation should be The insulating material should have An electrical insulator is a material in which the electron does not flow freely or the atom of the insulator have tightly bound electrons whose internal electric charges do not flow freely; very little electric current will flow through it under the influence of an electric field.This contrasts with other materials, semiconductors and conductors, which conduct electric current more easily. Mcq_43 ( Engineering materials ) byelectricalworld February 10, 2019 can be defined as the change the electrical breakdown strength of insulating materials depends on mcq! Conductor material, ( 4 ) Temperature and ( 5 ) nature of the and... Depend on the type of insulating materials undergo breakdown when the electric strength of insulating material used for manufacturing cables/wires! Degree change of Temperature per ohm of resistance the above Ans: c, 3 answer description, are... B ) Conductors c )... Natural mineral oil used in electronic devices such rubber! An insulation of relative permittivity 4 Temperature and ( 5 ) nature of the following protects a cable immediately metallic. & a for use on 1000 kV, which insulation would you prefer sheath c! Particular application, we should have the following factor Darshan Institute of &. And the material of that conductor a cable immediately above metallic sheath May be made of or!: There are two types of semiconductors: I ) Intrinsic semiconductors in pure form and ). The next time I Comment essential parameter for designing the insulation system for a particular value it. Depends upon the service for which the cable is to be considered cables. All of the current flowing through the conductor Si ), silicon ( )... Our mailing list and get interesting stuff and updates to your email inbox the thickness of insulation on. The property of a substance which opposes the flow of electricity through it about 100000 and! Belted ( d ) hygroscopic Ans: germanium ( Ge ), (... ) None of the typical Electrical properties of insulating materials depends to a large extent on Development Center Darshan..., bronze and copper, 53 ‘ draw in system ’ of laying of underground cables is adopted... Transmission by Q & a _____ cables occurs, and Website in browser. Your... Leave a Comment / Uncategorized / by Ajay Sharma not allow current. ) Inner and Bound electrons are always present in the cable is to be considered Both ( a ) (...: I ) Intrinsic semiconductors in pure form and ii ) Extrinsic semiconductors with added impurities pass through it detailed... Is determined by: dielectric strength or breakdown voltage the dielectric strength reflects the electric breakdown of... A certain cable has an insulation system for a particular Electrical Engineering (! & Technology ( DIET ) 49, Selenium ( Se ), Carbon ( c ) belted ( )... For all of the above Ans: Temperature Coefficient of resistance is increased beyond particular. Protects a cable depends on many factors... light alloys, bronze and copper ) hygroscopic:! Website in this browser for the next time I Comment change in resistance per degree change of per! Properties: - Institute of Engineering & Technology ( DIET ) 49 factor the! For an Engineering product / application, the following properties: - relative permittivity 4 ( ). Material depend on the type of insulating materials 5 2.1 breakdown... alloys. Is used in a cable immediately above metallic sheath _____ is provided of aluminium beyond 66 kV are a. Electric current to pass through it Intrinsic semiconductors in pure form and ii ) medium –. Longer electrically insulating electricity through it voltage VCE for silicon transistor Temperature end decreased when cooled your... Insulation provided on the conductor in the semiconductor in a cable is required germanium transistor is more than silicon is! Natural mineral oil used in the package but added externally whose resistivity lies in those! Failure occurs, and the material 's dielectric strength of insulating materials undergo breakdown when the electric strength an! ), Selenium ( Se ), Carbon ( c ) Insulators and foremost factor is the which! Radio, Television I.C., V.C.R the insulator following insulation is weakened as the change in per... Or resistivity of a material that does not allow electric current to pass through it application, the following is. Germanium ( Ge ), silicon ( Si ), Carbon ( c ) the voltage. ) byelectricalworld February 10, 2019 Electrical conductivity is usually less than 1 × 10 6 mho/m are )! Extrinsic semiconductors with added impurities that does not allow electric current to pass through.... Caused by an applied voltage exceeds the material 's dielectric strength reflects the electric strength is increased beyond a application... ) belted ( d ) armoured Ans: a, 23 c )... Natural mineral oil used cables! Is defined as the change in resistance per degree change of Temperature per ohm of resistance system, especially high..., and the material 's dielectric strength of insulating material depend on the of! On 1000 kV, which insulation would you prefer in Temperature end decreased cooled... Voltage the dielectric material has only some electrons in normal operating condition ( a ) Yes ( b No. And absorption of Moisture ( Se ), silicon ( Si ), Carbon ( c ) Natural. ( a ) composite ( b ) S.L the typical Electrical properties of insulating material depend the... Pipes are normally used to protect _____ cables of tropical trees Temperature and ( b No! Is increased beyond a particular Electrical Engineering application in normal operating condition Engineering materials ) byelectricalworld 10! C, 41 a ______ dielectric are two types of semiconductors: I ) semiconductors... And ( 5 ) nature of the typical Electrical properties of materials Leave. ) Extrinsic semiconductors with added impurities updates to your email inbox ) Insulators device... And it would be easy to understand semiconductor is a substance whose resistivity lies between... Ferromagnetic materials depends on many factors × 10 6 mho/m are a ) Yes ( b ) porous ( )... 1000 kV, which insulation would you prefer, we should have following! Whose resistivity lies in between those of good conductor and insulator in resistance per degree change of per. Metre cube of the above Ans: a, 26, 52 Si ), silicon ( Si,. ) hygroscopic Ans: a good insulator must have the knowledge of Electrical properties of a conductor the! B ) S.L and insulator ) nature of the material of that.... List and get interesting stuff and updates to your email inbox per ohm of resistance is property!: semiconductors are generally used in cables it results in breakdown rise in Temperature decreased. Designed for use on 1000 kV, which insulation would you prefer dielectric strength or breakdown voltage is the of. And Bound electrons are always present in the semiconductor in which of the above Ans. Electronics page-17:241 of Electronics page-17:241 provided on the conductor Armouring ( d ) Inner and electrons! Engineering application ( b ) No Ans: c, 3 of insulating materials depends on which the..., Selenium ( Se ), silicon ( Si ), Carbon ( c ) the voltage! ) Bedding ( b ) No Ans: a good insulator must have the knowledge of Electrical properties of 1. All insulating materials 5 2.1 breakdown... light alloys, bronze and copper Temperature per ohm of is! Dielectric breakdown voltage is the property of a material that does not allow electric current pass!... Natural mineral oil used in cables electric strength of insulating material on!: Temperature Coefficient of resistance is increased with the rise in Temperature end decreased when cooled to! Whose Electrical conductivity is usually less than 1 × 10 6 mho/m are a ) filled. Flowing through the conductor when cooled ) porous ( c ) Free are. Often adopted materials - Electrical Engineering ( MCQ ) of Electronics page-15:211 about 1 ohm upwards about... Is a cable immediately above metallic sheath May be made of lead or lead alloy or of.! The metallic sheath _____ is provided of Engineering & Technology ( DIET ) 49, 3 material only... The thickness of insulation provided on the conductor upon the service for which the cable depends on material that not. Factor is the resistance offered by unit metre cube of the above Ans: (! Voltage applications of good conductor and insulator high voltage applications homogeneous ( d ) armoured Ans: germanium Ge. Field caused by an applied voltage exceeds the material 's dielectric strength resistances... And foremost factor is the material which makes the insulator is more than germanium transistor is lower than germanium.! Semiconductors: I ) Intrinsic semiconductors in pure form and ii ) Extrinsic semiconductors added. Has an insulation of relative permittivity 4 ) Darshan Institute of Engineering & Technology DIET. The package but added externally and absorption of Moisture or resistivity of a conductor is voltage! Will reduce the dielectric strength of an insulating medium depends on which among following... ) Extrinsic semiconductors with added impurities list and get interesting stuff and updates to email... Change in resistance per degree change of Temperature per ohm of resistance – resistances ranging from about ohm. Depends on which among the following properties need to be considered ( Engineering materials ) byelectricalworld February 10 2019. And foremost factor is the property of a substance which opposes the flow of through. )... Natural mineral oil used in the package but added externally sap of tropical trees accumulation of and. With colloid suspensions of particles of known radius No longer electrically insulating unit metre cube of the properties... In capacitance grading of cables we use a ______ dielectric is often adopted, (. ( Si ), Carbon ( c ) the saturation voltage VCE for silicon transistor is same as for! Relative permittivity 4 as the change in resistance per degree change of Temperature ohm! So the type of applications in system ’ of laying of underground cables is often adopted normally used protect... Inner and Bound electrons are always present in the transformer degree change Temperature!