Description : Skin depth phenomenon is found in which materials? a) Insulators b) Dielectrics c) Conductors d) Semiconductors
Last Answer : c) Conductors
Description : Materials exhibiting zero value of resistivity are known as ______ . (a) conductors (b) semiconductors (c) insulators (d) superconductors
Last Answer : (d) superconductors
Description : The skin effect is a phenomenon observed in a) Insulators b) Dielectrics c) Conductors d) Semiconductors
Description : Dielectric constant will be high in a) Conductors b) Semiconductors c) Insulators d) Superconductors
Last Answer : c) Insulators
Description : Substances of conductivity between 10–10 10–20 (n m )–1 are: a) Insulators b) Semiconductors c)Super conductors d)Good conductors
Last Answer : a) Insulators
Description : he substances of conductivity of the order of 10–6 – 10–4 (m)–1 are : a) Insulators b) Super conductors c) Semiconductors d)Good conductors
Last Answer : d)Good conductors
Description : Ceramics are good (A) insulators. (B) conductors. (C) superconductors. (D) semiconductors.
Last Answer : (A) insulators.
Description : Classify the solids into conductors, semiconductors and insulators on the basis of band theory of solids.
Last Answer : In conductors there is no energy gap between valance band and conduction band, they are overlapped on each other. So electrons can jump from valance band to conduction band easily and material ... band when some amount of energy is supplied to it. Therefore insulators cannot conduct the current.
Description : Name two good conductors, two good insulators, and two semiconductors.
Last Answer : In general all metals are good conductors, with silver the best and copper second.
Description : Practical method of improving string efficiency a) Increasing crass arms length b) Using different size of insulators c) Using different insulator materials d) Using of guard rings
Last Answer : Ans: Increasing crass arms length*
Description : Magnetic materials (A) provide path to magnetic flux. (B) are good insulators. (C) are semiconductors. (D) None.
Last Answer : (A) provide path to magnetic flux.
Description : The covers of electrical machines are made of (A) soft magnetic materials. (B) hard magnetic materials. (C) super conductors. (D) semiconductors.
Last Answer : (A) soft magnetic materials.
Description : Hard magnetic materials are used for making (A) Permanent magnets. (B) Temporary magnets. (C) Conductors. (D) Insulator.
Last Answer : (A) Permanent magnets.
Description : Transistors are made from (a) Plastic (b) metals (c)insulators (d) doped semiconductors
Last Answer : d) doped semiconductors
Description : Holes are majority carriers in (A) P-type semiconductors. (B) N-type semiconductors. (C) Insulators. (D) Superconductors.
Last Answer : (A) P-type semiconductors.
Description : This group of alumino-silicate minerals is widely used in making electrical insulators (1) Bauxite (2) Chrornite (3) Manganese (4) Mica
Last Answer : (4) Mica Explanation: Sheet mica is used principally in the electronic and electrical industries. Its usefulness in these applications is derived from its unique electrical and thermal insulating properties and ... it is a good electrical insulator at the same time as being a good thermal conductor.
Description : This group of alumino-silicate minerals is widely used in making electrical insulators (1) Bauxite (2) Chromite (3) Manganese (4) Mica
Last Answer : Mica
Description : Pure semiconductors silicon and germanium are a) Extrinsic b) Intrinsic c) Insulator d) Diodes
Last Answer : b) Intrinsic
Description : Compare pin type and suspension insulators on given points: (i) Position of insulator on cross arm. (ii) Position of conductor on insulator. (iii) Reaction on cross arm. (iv) Possibility of ... Replacement cost (vi) Maximum voltage level (vii) Effect on height of supporting structure. (viii) Life
Last Answer : S.No Points Pin Type insulator Suspension or Disc Type insulator 1 Position of insulator on cross arm It is fixed on top of cross arm by using galvanized steel pin. So it is ... so to maintain minimum ground clearance height of pole increase. 8 Life Less More
Description : Hall effect is associated with (A) Conductors. (B) Semiconductors. (C) Thermistors. (D) Solders.
Last Answer : (B) Semiconductors.
Description : What is more important insulators or conductors?
Last Answer : Both are equally important.Insulators keep the electricity from going where it is notwanted while conductors take electricity where it is wanted.
Description : What is more important conductors or insulators?
Last Answer : Conductors and Insulators. In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.
Description : Are perspex and polythene conductors r insulators?
Last Answer : ?
Description : Name three electrical conductors and three electrical insulators.
Last Answer : Ans: conductors: metals, graphite, carbon insulators: glass, rubber, wood
Description : The substances which have a large number of free electrons and offer a low resistance are called (a) insulators (b) inductors (c) semi-conductors (d) conductors
Last Answer : (d) conductors
Description : The use of strain type insulators is made where the conductors are (a) dead ended (b) at intermediate anchor towers (c) any of the above (d) none of the above
Last Answer : (c) any of the above
Description : Which have more free electrons: conductors or insulators?
Last Answer : Conductors have many free electrons whereas insulators have very few or none at all.
Description : Polytetrafluoroethylene (PTFE) is also widely used insulator and is known as. A. polystyrene B. teflon C. ceramic D. bakelite
Last Answer : B. teflon
Description : Heating of ferromagnetic materials to a temperature above Curie temperature makes it (A) Insulator for heat & electricity transmission (B) Ferritic (C) Behave like paramagnetic materials (D) Superconductor
Last Answer : Option C
Description : Strong and ductile materials (a) Polymers (b) Ceramics (c) Metals (d) Semiconductors
Last Answer : (c) Metals
Description : Which of the listed pairs of materials make the best insulators? A. dry air and a vacuum B. tin and lead C. doped silicon and germanium D. paper and oil
Last Answer : Answer: D
Description : Which of the listed pairs of materials make the best insulators? A. copper and aluminum B. glass and mica C. dry air and a vacuum D. doped silicon and germanium
Last Answer : Answer: B
Description : Assertion : Zone refining method is very useful for producing semiconductors. Reason : Semiconductors are of high purity.
Last Answer : Assertion : Zone refining method is very useful for producing semiconductors. Reason : Semiconductors are of high purity.
Description : Which of the following materials is a good insulator? A. steel B. aluminum C. glass D. copper
Last Answer : Answer: C
Description : Which of the following materials is a good electrical insulator? A. wood B. silver C. copper D. gold
Last Answer : Answer: A
Description : Materials having resistivity ranging from 1 to 100 ohm. cm is termed as (A) Conductor (B) Insulator (C) Semi-conductor (D) None of these
Last Answer : (C) Semi-conductor
Description : What three materials that are good conductors of heat?
Last Answer : Feel Free to Answer
Description : Ceramic materials are (A) Organic in nature (B) Stronger in compression than in tension (C) Always amorphous in nature (D) Always bad heat conductors
Last Answer : (B) Stronger in compression than in tension
Description : Ceramic materials (A) Are exemplified by clay and mica (B) Are poor electrical conductors due to lack of free electrons (C) Never exhibit polymorphism (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Permanent magnets are made of (A) soft magnetic materials. (B) hard magnetic materials. (C) semi conductors. (D) super conductors.
Last Answer : (B) hard magnetic materials.
Description : Materials which can store electrical energy are called (A) magnetic materials. (B) semi conductors. (C) dielectric materials. (D) super conductors.
Last Answer : (C) dielectric materials.
Description : Pick out the wrong statement. (A) For the manufacture of styrene, the major raw materials are benzene and ethylene (B) One important copolymer of styrene is SBR, which is widely ... D) Phenol manufacture by chlorobenzene-caustic process is competitive even when low cost chlorine is not available
Last Answer : (D) Phenol manufacture by chlorobenzene-caustic process is competitive even when low cost chlorine is not available
Description : Agitator is provided in a crystalliser for (A) Avoiding deposition on cooler surfaces (B) Formation of nuclei (C) Crystal growth (D) All (A), (B) and (C)
Description : The McCabe ΔL law states that the (A) Molar heats of vaporisation of components are nearly equal (B) Linear crystal growth rate depends on the degree of super-saturation (C) Linear ... does not depend on the crystal size (D) Linear crystal growth rate depends on the crystal size
Last Answer : (C) Linear crystal growth rate does not depend on the crystal size
Description : Pick out the wrong statement. (A) Swenson-Walker crystalliser is a batch crystalliser (B) Super saturation of the solution is the driving potential for a crystal growth (C) The ... a solution is called mother liquor (D) The first stage of crystal formation is called nucleation
Last Answer : (A) Swenson-Walker crystalliser is a batch crystalliser
Description : The driving potential for the crystal growth during crystallisation is the __________ of the solution. (A) Concentration (B) Viscosity (C) Super-saturation (D) Density
Last Answer : (C) Super-saturation
Description : Write the process that result in the growth of lateral buds and widely applied in tea plantations and hedge making.
Last Answer : Write the process that result in the growth of lateral buds and widely applied in tea plantations and hedge making.