Electrical Engineering MCQs [Set 3]

21. Mercury as an electric contact material is
(a) a liquid
(b) a metal
(c) a metal liquid
(d) a gas

22. An H.R.C. fuse is
(a) a ceramic body having metal and caps
(b) a wire of platinum
(c) a heavy cross-section of copper or aluminium
(d) a ceramic tube having carbon rod inside it

23. Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
(a) Nichrome
(b) Constantan
(c) Kanthal
(d) Molybdenum

24. The coils of D.C. motor starter are wound with wire of
(a) copper
(b) kanthal
(c) manganin
(d) nichrome

25. The conductors have transport phenomena of electrons due to
(a) electric field
(b) magnetic field
(c) electromagnetic field
(d) none of the above

26. The transition temperature of mercury is
(a) 18.0°K
(6) 9.22°K
(c) 4.12°K
(d) 1.14’K

27. By increasing impurity content in the metal alloy the residual resistivity always
(a) decreases
(b) increases
(c) remains constant
(d) becomes temperature independent

28. The structure sensitive property of a super conductor is
(a) critical magnetic field
(b) transition temperature
(c) critical current density
(d) none of the above

29. At transition temperature the value of critical field is
(a) zero
(6) negative real value
(c) positive real value
(d) complex value

30. Which of the following variety of copper has the best conductivity ?
(a) Induction hardened copper
(b) Hard drawn copper
(c) Pure annealed copper
(d) Copper containing traces of silicon

Updated: 29th June 2019 — 8:28 PM

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