- A. Fe203
- B. Si02
- C. AI2O3
- D. B2O3
Electrical Engineering Materials
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__________ is the main constituent of glass.
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On which of the following factors does the resistivity of a material depend ?
- A. Resistance of the conductor
- B. Area of the conductor section
- C. Length of the conductor
- D. All of the above
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High resistivity materials are used in_____.
- A. Precision instruments
- B. Heating elements
- C. Motor starters
- D. Incandescent lamps
- E. All of the above
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The covalent bond is formed by_____.
- A. Transfer of electrons between atoms
- B. Sharing of electrons between atoms
- C. Sharing of variable number of electrons by a variable number of atoms
- D. None of the above
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The kinetic energy of a bounded electron is_____.
- A. Less than that of unbounded electron
- B. Greater than that of unbounded electron
- C. Equal to that of unbounded electron
- D. Infinite
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Surface resistance of an insulating material is reduced due to the_____.
- A. Smoky and dirty atmosphere
- B. Humidity in the atmosphere
- C. Both A and B
- D. Neither A nor B
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Total number of crystal systems is_____.
- A. 2
- B. 4
- C. 7
- D. 12
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A carbon resistor contains_____.
- A. Carbon crystals
- B. Solid carbon granules
- C. Pulverized coal
- D. Finely divided carbon black
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The superconductivity is due to_____.
- A. The crystal structure having no atomic vibration at 0°K
- B. All electrons interact in the super-conducting state
- C. The electrons jump into nucleus at 0°K
- D. None of the above
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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