Electrical Engineering Materials(Engineering > Electrical Engineering ) Questions and Answers

Question 1. A carbon resistor contains
  1.    Carbon crystals
  2.    Solid carbon granules
  3.    Pulverized coal
  4.    Finely divided carbon black.
Explanation:-
Answer: Option D. -> Finely divided carbon black.
Question 2. The forbidden gap in an insulator is
  1.    Large
  2.    Small
  3.    Nil
  4.    Any of the above
Explanation:-
Answer: Option A. -> Large
Question 3. Which of the following material is not a semiconductor ?
  1.    Silica
  2.    Germanium
  3.    Selenium
  4.    Gallium-arsenide
Explanation:-
Answer: Option A. -> Silica
Question 4. Which of the following materials is preferred for transmitting electrical energy over long distance ?
  1.    Copper
  2.    Aluminium
  3.    Steel reinforced copper
  4.    Steel reinforced aluminium
Explanation:-
Answer: Option D. -> Steel reinforced aluminium
Question 5. Platinum is used in
  1.    Electrical contacts
  2.    Thermocouple
  3.    Heating element in high temperature furnace
  4.    Grids of special purpose vacuum tubes
  5.    All of the above
Explanation:-
Answer: Option E. -> All of the above
Question 6. In a crystal, an atom vibrates at a frequency determined by
  1.    The heat content of the crystal
  2.    The temperature of the crystal
  3.    The stiffness of the bonds it makes with neighbors
  4.    All of the above
Explanation:-
Answer: Option C. -> The stiffness of the bonds it makes with neighbors
Question 7. Due to which of the following reasons copper and aluminium are not used for heating elements ?
  1.    Both have great tendency for oxidation
  2.    Both have low melting point
  3.    Very large length of wires will be required
  4.    All of the above
Explanation:-
Answer: Option D. -> All of the above
Question 8. Which of the following high resistance materials has the highest operating temperature ?
  1.    Kanthal
  2.    Manganin
  3.    Nichrome
  4.    Eureka
Explanation:-
Answer: Option A. -> Kanthal
Question 9. Thermocouples are mainly used for the measurement of
  1.    Temperature
  2.    Resistance
  3.    Eddy currents
  4.    Coupling co-efficient
Explanation:-
Answer: Option A. -> Temperature
Question 10. The transition temperature of mercury is
  1.    18.0°K
  2.    9.22°K
  3.    4.12°K
  4.    1.14’K
Explanation:-
Answer: Option C. -> 4.12°K
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