51. The value of critical field below the transition temperature will A. Increase B. Decrease C. Remain unchanged 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
52. Is viscoelastic. A. Cast-iron B. Graphite C. Rubber D. Glass 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
53. Which of the following factors affect resistivity of metals ? A. Age hardening B. Alloying C. Temperature D. Cold work 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
54. By increasing impurity content in the metal alloy the residual resistivity always A. Decreases B. Increases C. Remains constant D. Becomes temperature independent Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
55. Carbon bearings are used under which of the following conditions ? A. Where lubrication is difficult or im-possible B. Where corrosive chemical action exists C. Where high temperature exists 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
56. For a hole which of the following statements is incorrect ? A. Holes can exist in certain semiconductors only B. Holes can exist in any material including conductors C. Holes may constitute an electric current D. Holes can be considered as a net positive charge Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
57. Substances whose specific resistance abruptly decreases at very low temperature are called A. Insulators B. Conductors C. Semiconductors D. Superconductors 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
58. 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 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
59. The photo-electric effect occurs only when the incident light has more than a certain critical A. Intensity B. Speed C. Frequency D. Wave length 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
60. Carbon rods are used in wet and dry cells because 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 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