[{"id":127530,"question":"The magnetism produced by electrons within an atom can arise from","choices":[{"text":"electrons orbiting the nucleus","value":"A"},{"text":"electrons orbiting the nucleus","value":"B"},{"text":"both motions","value":"C"},{"text":"none one these motions","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127517,"question":"Recently a complex crystalline structure known as Yetrium Barium Copper Oxide have been reported to become superconductor at","choices":[{"text":"125 K","value":"A"},{"text":"25 K","value":"B"},{"text":"263 K","value":"C"},{"text":"163 K","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":127516,"question":"Any superconductor with critical temperature above 77 K, is referred as","choices":[{"text":"low temperature superconductor","value":"A"},{"text":"high temperature superconductor","value":"B"},{"text":"very low temperature superconductor","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127514,"question":"The critical temperature of lead is","choices":[{"text":"1.18 K","value":"A"},{"text":"4.2 K","value":"B"},{"text":"3.72 K","value":"C"},{"text":"7.2 K","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":127513,"question":"The critical temperature of tin is","choices":[{"text":"1.18 K","value":"A"},{"text":"4.2 K","value":"B"},{"text":"3.72 K","value":"C"},{"text":"7.2 K","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127512,"question":"The critical temperature of aluminum is","choices":[{"text":"1.18 K","value":"A"},{"text":"4.2 K","value":"B"},{"text":"3.72 K","value":"C"},{"text":"7.2 K","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127511,"question":"The critical temperature of mercury is","choices":[{"text":"1.18 K","value":"A"},{"text":"4.2 K","value":"B"},{"text":"3.72 K","value":"C"},{"text":"7.2 K","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127510,"question":"There are some materials whose resistivity becomes zero below a certain temperature, called","choices":[{"text":"absolute zero","value":"A"},{"text":"0<span style=\"color: rgb(84, 84, 84); font-family: arial, sans-serif; font-size: small;\">° C</span>","value":"B"},{"text":"critical temperature","value":"C"},{"text":"lower fixed point","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127509,"question":"In a semi-conductor material, the total current is","choices":[{"text":"only the +ve current","value":"A"},{"text":"only the electronic current","value":"B"},{"text":"sum of +ve and electronic current","value":"C"},{"text":"all of them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127508,"question":"In a semi-conductor material, current flows due to","choices":[{"text":"positive charge","value":"A"},{"text":"negative charge","value":"B"},{"text":"both of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127507,"question":"Whenever a covalent bond is broken in an intrinsic semi-conductor","choices":[{"text":"hole is created","value":"A"},{"text":"an electron is created","value":"B"},{"text":"an electron hole is generated","value":"C"},{"text":"all of them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127505,"question":"When a silicon crystal is doped with a trivalent element, then the atom of the trivalent element is known as","choices":[{"text":"acceptor","value":"A"},{"text":"donor","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127503,"question":"When a silicon crystal is doped with a pentavalent element, then the atom of the pentavalent element is known as","choices":[{"text":"acceptor","value":"A"},{"text":"donor","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127499,"question":"A hole in a semi-conductor material is treated as","choices":[{"text":"positive charge","value":"A"},{"text":"negative charge","value":"B"},{"text":"neutral","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127497,"question":"When a silicon crystal is doped with a trivalent element, such an extrinsic semi-conductor is called","choices":[{"text":"p-type semi-conductor","value":"A"},{"text":"n-type semi-conductor","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127494,"question":"When a sillicon crystal is doped with a pentavalent element, such an extrinsic semi-conductor is called","choices":[{"text":"p-type semi-conductor","value":"A"},{"text":"n-type semi-conductor","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127493,"question":"Arsenic, antimony and phosphorous are the elements from","choices":[{"text":"third group","value":"A"},{"text":"fourth group","value":"B"},{"text":"fifth group","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127491,"question":"The bonding between the semi-conductor materials is","choices":[{"text":"covalent","value":"A"},{"text":"ionic","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127490,"question":"Semi-conductor elements have atoms with","choices":[{"text":"2 valence electrons","value":"A"},{"text":"3 valence electrons","value":"B"},{"text":"4 valence electrons","value":"C"},{"text":"5 valence electrons","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127488,"question":"The doped semi-conductors materials are known as","choices":[{"text":"intrinsic semi-conductor","value":"A"},{"text":"extrinsic semi-conductor","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127486,"question":"In the doping process, the ratio of the doping atoms to the semi-conductor atom is","choices":[{"text":"1 to 10","value":"A"},{"text":"1 to 10<sup>3</sup>","value":"B"},{"text":"1 to 10<sup>6</sup>","value":"C"},{"text":"1 to 10<sup>9</sup>","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127484,"question":"When small number of atoms from some other suitable element is added to the semi-conductor material, then this process is known as","choices":[{"text":"impurification","value":"A"},{"text":"adding","value":"B"},{"text":"doping","value":"C"},{"text":"extrinsivity","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127482,"question":"A semi conductor in its extremely pure from is known as","choices":[{"text":"extrinsic semi-conductor","value":"A"},{"text":"intrinsic semi-conductor","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127480,"question":"Conductors are those materials in which energy gap is","choices":[{"text":"very large (several eV)","value":"A"},{"text":"very narrow (= 1eV)","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":127478,"question":"Insulators are those material in which energy gap is","choices":[{"text":"very large (several eV)","value":"A"},{"text":"very narrow (= 1ev)","value":"B"},{"text":"either of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127477,"question":"The materials in which there are plenty of free electrons for electrical conduction are known as","choices":[{"text":"conductors","value":"A"},{"text":"insulators","value":"B"},{"text":"semi-conductors","value":"C"},{"text":"all of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127475,"question":"The materials in which valence electrons are bound very tightly to their atoms and are not free, are known as","choices":[{"text":"conductors","value":"A"},{"text":"insulators","value":"B"},{"text":"semi-conductors","value":"C"},{"text":"all of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127473,"question":"The bands below the valence band are","choices":[{"text":"completely filled and play active part in conduction process","value":"A"},{"text":"completely filled and plays no part in conduction process","value":"B"},{"text":"not completely filled and play active part in conduction process","value":"C"},{"text":"not completely filled and play no part in conduction process","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127471,"question":"The conduction band in a solid","choices":[{"text":"may be empty","value":"A"},{"text":"cannot be empty","value":"B"},{"text":"should be filled","value":"C"},{"text":"all of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127469,"question":"The electrons occupying the conduction band are known as","choices":[{"text":"conduction electrons","value":"A"},{"text":"free electrons","value":"B"},{"text":"both of them","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127468,"question":"The band above the valence band is called","choices":[{"text":"high energy band","value":"A"},{"text":"conduction band","value":"B"},{"text":"empty band","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127466,"question":"The valence band of an atom in a solid","choices":[{"text":"is always empty","value":"A"},{"text":"may or may not be empty","value":"B"},{"text":"can never be empty","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127464,"question":"When a large number of atoms are brought close to one another to form a solid, each energy level of an isolated atom splits into sub-levels, called","choices":[{"text":"energy bands","value":"A"},{"text":"energy shells","value":"B"},{"text":"states","value":"C"},{"text":"all of them","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":127463,"question":"Electrons of an isolated atom are bound to the nucleus, and?","choices":[{"text":"can only have distinct energy level","value":"A"},{"text":"can only have same energy level","value":"B"},{"text":"may or may not have distinct energy","value":"C"},{"text":"none of them","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127462,"question":"Which of the following theory completely explain the three types of materials?","choices":[{"text":"Bohr model of electron distribution","value":"A"},{"text":"Rutherford atomic model","value":"B"},{"text":"Pauli's exclusion principle","value":"C"},{"text":"energy band theory","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":127455,"question":"The electrical conductivities of insulators are ranging from","choices":[{"text":"10<sup>-5</sup>to 10<sup>-10 </sup>(<span style=\"color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)</b><sup>-1</sup></span>","value":"A"},{"text":"10<sup>-10</sup>to 10<sup>-15</sup>(<span style=\"font-family: &quot;Times New Roman&quot;; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)</b><sup>-1</sup></span>","value":"B"},{"text":"10<sup>-5</sup>to 10<sup>-15</sup>(<span style=\"font-family: &quot;Times New Roman&quot;; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)</b><sup>-1</sup></span>","value":"C"},{"text":"10<sup>-10</sup>to 10<sup>-20</sup>(<span style=\"font-family: &quot;Times New Roman&quot;; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)</b><sup>-1</sup></span>","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":127454,"question":"Metals are good conductors of electricity and their conductivities are of the order of","choices":[{"text":"10<sup>3</sup>(<span style=\"color: rgb(34, 34, 34); font-family: &quot;Times New Roman&quot;; font-size: 24px; text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)<sup>-1</sup></b></span>","value":"A"},{"text":"10<sup>4</sup>(<span style=\"font-family: &quot;Times New Roman&quot;; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)<sup>-1</sup></b></span>","value":"B"},{"text":"10<sup>6</sup>(<span style=\"font-family: &quot;Times New Roman&quot;; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)<sup>-1</sup></b></span>","value":"C"},{"text":"10<sup>7</sup>(<span style=\"font-family: &quot;Times New Roman&quot;; font-size: 24px; color: rgb(34, 34, 34); text-align: center; background-color: rgb(255, 255, 224);\"><b>Ω m)<sup>-1</sup></b></span>","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":127453,"question":"Lead, copper and wrought iron are examples of","choices":[{"text":"brittle substances","value":"A"},{"text":"ductile substances","value":"B"},{"text":"plastic substances","value":"C"},{"text":"elastic substances","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127452,"question":"Glass and high carbon steel are the examples of","choices":[{"text":"brittle substances","value":"A"},{"text":"ductile substances","value":"B"},{"text":"plastic substances","value":"C"},{"text":"elastic substances","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":127451,"question":"The substances which break just after the elastic limit is reached, are known as","choices":[{"text":"brittle substances","value":"A"},{"text":"ductile substances","value":"B"},{"text":"plastic substances","value":"C"},{"text":"elastic substances","value":"D"},{"value":"E"}],"correctAnswer":1}]