71. A carbon resistor contains A. Carbon crystals B. Solid carbon granules C. Pulverized coal D. Finely divided carbon black. Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
72. Which of the following material is not a semiconductor ? A. Silica B. Germanium C. Selenium D. Gallium-arsenide Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
73. Which of the following materials is preferred for transmitting electrical energy over long distance ? A. Copper B. Aluminium C. Steel reinforced copper D. Steel reinforced aluminium Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
74. The forbidden gap in an insulator is A. Large B. Small C. Nil D. Any of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
75. 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 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option E No explanation is given for this question Let's Discuss on Board
76. In a crystal, an atom vibrates at a frequency determined by A. The heat content of the crystal B. The temperature of the crystal C. The stiffness of the bonds it makes with neighbors D. All of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
77. 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 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
78. Thermocouples are mainly used for the measurement of A. Temperature B. Resistance C. Eddy currents D. Coupling co-efficient Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
79. Which of the following high resistance materials has the highest operating temperature ? A. Kanthal B. Manganin C. Nichrome D. Eureka Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
80. The transition temperature of mercury is A. 18.0°K B. 9.22°K C. 4.12°K D. 1.14°K Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
