ECAT Pre General Science Physics Chapter 17 Physics of Solids Online Test With Answers

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ECAT Pre General Science Physics Chapter 17 Physics of Solids Online Test

Sr. # Questions Answers Choice
1 Ferromagnetic substances lose their magnetism when heated above a certain temperature, known as critical temperature curie temperature high temperature fixed temperature
2 Which of the following can become a good temporarily magnet iron steel both of them none of them
3 Which of the following can become a good permanent magnet iron steel both of them none of them
4 In a soft iron, domains are easily oriented along external field and do not return to original random positions easily oriented along external field and readily returns to originally random position do no oriented along external field and also do not returns to originally random position none of them
5 Within each domain, the magnetic field of all the spinning electrons are parallel antiparallel perpendicular all of them
6 The size of the domain is such that they can contain 10<sup>2</sup>to 10<sup>4</sup>atoms 10<sup>4</sup> to 10<sup>8</sup>atoms 10<sup>8</sup>to 10<sup>12</sup>atoms 10<sup>12</sup>to 10<sup>16</sup>atoms
7 The domains are of macroscopic size of the order of centimeters meters millimeters nanomneters
8 Recent studies of ferromagnetism have shown that there exists in ferromagnetic substances small regions called tiny regions domains vectors none of them
9 The substance in which atoms cooperate with each other in such a way so as to exhibit a strong magnetic effect, are called diamagnetic substances ferromagnetic substances paramagnetic substances all of them
10 The substance in which atoms are so oriented that the field produced by spin and orbital motion of the electrons might add up to zero,are called diamagnetic substances ferromagnetic substances paramagnetic substances all of them
11 The substances in which, atom are so oriented that their fields support each other and the atoms behave like tiny magnets, are called diamagnetic substances ferromagnetic substances paramagnetic substances all of them
12 The charged nucleus of an atom itself spins its magnetic field equal to the field produced by orbital electrons greater than the field produced by orbital electrons much weaker than the field produced by orbital electrons none of these
13 An atom in which there is a resultant magnetic field, behaves like a tiny magnet and is called as magnetic magnetic dipole magnetic monopole none of them
14 The magnetism produced by electrons within an atom can arise from electrons orbiting the nucleus electrons posses a spin both motions none of these motions
15 Recently a complex crystalline structure known as Yetrium Barium Copper Oxide have been reported to become superconductor at 125 K 25 K 263 K 163 K
16 Any superconductor with critical temperature above 77 K, is referred as low temperature superconductor high temperature superconductor very low temperature superconductor none of them
17 The critical temperature of tin is 1.18 K 4.2 K 3.72 K 7.2 K
18 The critical temperature of aluminium is 1.18 K 4.2 K 3.72 K 7.2 K
19 The critical temperature of mercury is 1.18 K 4.2 K 3.72 K 7.2 K
20 The first super conductor was discovered in 1811 1890 1901 1911
21 There are some whose resistivity becomes zero below a certain temperature, called absolute zero 0<span style="color: rgb(84, 84, 84); font-family: arial, sans-serif; font-size: small;">°C</span> critical temperature lower fixed point
22 In a semi-conductor material, the total current is only the +ve current only the electronic current sum of +ve and electronic current all of them
23 In a semi-conductor material, current flows due to positive charge negative charge both of them none of them
24 Whenever a covalent bond is broken in an intrinsic semi-conductor hole is created an electron is created an electron-hole pair is generated all of them
25 When a silicon crystal is doped with a pentavalent element, then the atom of the pentavalent element is known as acceptor donor either of them none of them
26 When a silicon crystal is doped with a pentavalent element, such an extrinsic semi-conductor is called p-type semi-conductor n-type semi-conductor either of them none of them
27 Arsenic, antimony and phosphorus are the elements from third group fourth group fifth group none of them
28 The bonding between the semi-conductor materials is covalent ionic either of them none of them
29 Semi-conductor elements have atoms with 2 valence electrons 3 valence electrons 4 valence electrons 5 valence electrons
30 The doped semi-conductor materials are known as intrinsic semi-conductor extrinsic semi-conductor either of them none of them
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