The conductivity of a metal is determined by____________?
(A) the electronic concentration and the mobility of the free electrons
(B) the number of valence electrons per atom
(C) either (A) or (B)
(D) none of the above
is the property of absorbing moisture from atmosphere_____________?
(A) Solubility
(B) Viscosity
(C) Porosity
(D) Hygroscopicity
Substances whose specific resistance abruptly decreases at very low temperature are called___________?
(A) insulators
(B) conductors
(C) semiconductors
(D) superconductors
Which of the following is an advantage of stranded conductor over equivalent single conductor ?
(A) Less liability to kink
(B) Greater flexibility
(C) Less liability to break
(D) All of the above
Which of the following materials is used for making coils of standard resistances ?
(A) Copper
(B) Nichrome
(C) Platinum
(D) Manganin
Low resistivity materials are used in__________?
(A) transformer, motor and generator windings
(B) transmission and distribution lines
(C) house wiring
(D) all above applications
Which of the following high resistance materials has the highest operating temperature ?
(A) Kanthal
(B) Manganin
(C) Nichrome
(D) Eureka
Platinum is used in_____________?
(A) electrical contacts
(B) thermocouple
(C) heating element in high temperature furnace
(D) grids of special purpose vacuum tubes
(D) all of the above
Steel wire is used as____________?
(A) overhead telephone wire
(B) earth wire
(C) core wire of ACSR
(D) all of the above