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.Management Sciences
Category: Electrical Engineering Materials
Carbon rods are used in wet and dry cells because_____________?
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A. carbon rod serves as conductor
B. carbon can resist the attack of battery acid
C. both (A) and (B)
D. either (A) or (B)
is a negatively charged particle present in an atom______________?
A. Proton
B. Neutron
C. Electron
D. None of the above
Which of the following material is not a semiconductor ?
A. Silica
B. Germanium
C. Selenium
D. Gallium-arsenide
Which of the following high resistance materials has the highest operating temperature ?
A. Kanthal
B. Manganin
C. Nichrome
D. Eureka
Commonly used conducting materials are_____________?
A. copper
B. aluminium
C. both (A) and (B)
D. copper and silver
E. platinum and gold
The impurity atoms is semiconductors_____________?
A. inject more charge carriers
B. reduce the energy gap
C. increase the kinetic energy of valence electrons
D. all of the above
Piezoelectric materials serve as a source of ____________ ?
A. resonant waves
B. musical waves
C. microwaves
D. ultrasonic waves
Due to which of the following reasons copper and aluminium are not used for heating elements ?
A. Both have great tendency for oxidation
B. Both have low melting point
C. Very large length of wires will be required
D. All of the above
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