Electrical Engineering Materials Objective type Questions and Answers pdf

61.    Which of the following material is not a semiconductor ?
(a)     Silica
(b)     Germanium
(c)     Selenium
(d)     Gallium-arsenide
Ans: a

62.    Carbon resistors are used extensively because they are
(a)     easy to make 
(b)     compact
(c)    inexpensive
(d)    all of the above reasons
Ans: d

63.    Carbon rods are used in wet and dry cells because
(a)     carbon rod serves as conductor
(b)     carbon can resist the attack of bat¬tery acid
(c)    both (a) and (b)
(d)    either (a) or (b)
Ans: c

64.    Due to which of the following factors the brush wear rate is altered ?
(a)     Speed of the machine
(b)     Contact pressure
(c)    Surface conditions of brush and commutator
(d)    Excessive sparking
(e)    All of the above
Ans: e

65.    Which of the following are non-conductors of electricity?
(a)     Non-metal solids except carbon
(b)     Air and most other gases
(c)    Pure water and liquids in general except mercury
(d)    All of the above
Ans: d

66.    Carbon bearings are used under which of the following conditions ?
(a)    Where lubrication is difficult or im-possible
(b)    Where corrosive chemical action exists
(c)    Where high temperature exists
(d)     All of the above
Ans: d

67. Which of the following high resistance materials has the highest operating temperature ?
(a)     Kanthal
(b)     Manganin
(c)     Nichrome
(d)     Eureka
Ans: a

68.    Steel wire is used as
(a)     overhead telephone wire
(b)     earth wire
(c)    core wire of ACSR
(d)    all of the above
Ans: d

69.    Low resistivity materials are used in
(a)    transformer, motor and generator windings
(b)    transmission and distribution lines
(c)    house wiring
(d)    all above applications
Ans: d

70.    Platinum is used in
(a)    electrical contacts
(b)    thermocouple
(c)    heating element in high temperature furnace
(d)    grids of special purpose vacuum tubes
(e)    all of the above
Ans: e

Read More Questions:
Electrical Engineering Materials MCQs Part1
Electrical Engineering Materials MCQs Part2
Electrical Engineering Materials MCQs Part3
Electrical Engineering Materials MCQs Part4
Electrical Engineering Materials MCQs Part5
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Electrical Engineering Materials MCQs Part7
Electrical Engineering Materials MCQs Part8
Electrical Engineering Materials MCQs Part9
Electrical Engineering Materials MCQs Part10