291. Which of the following pair does not match?

1. 1. Bond angle in diamond 109·5°

   
   
   

   2. Conduction in copper wire Free electron

   
   
   

   3. An example of hydrogen bond Hydrogen

   
   
   

   4. Thermal expansion in metallic Ionic bond bond is greater than that in

   
   
   

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   NA

   Correct Option: C

   NA

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292. The rate of diffusion process will increase if temperature is:

1. 1. decreased

   
   
   

   2. increased

   
   
   

   3. constant

   
   
   

   4. sub-zero

   
   
   

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   The rate of diffusion process will increase if temperature is increased.

   Correct Option: B

   The rate of diffusion process will increase if temperature is increased.

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293. Which of the following is not a thermally actuated process?

1. 1. Recrystallization of metal

   
   
   

   2. Creep of I. C. engine piston

   
   
   

   3. Vulcanization of rubber

   
   
   

   4. None of the above

   
   
   

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   NA

   Correct Option: D

   NA

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294. Activation energy is the potential energy that brings:

1. 1. unstable material into metastable state

   
   
   

   2. unstable material into stable state

   
   
   

   3. metastable material into stable state

   
   
   

   4. stable material into metastable state

   
   
   

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   NA

   Correct Option: A

   NA

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295. Out of the 4 electrode materials, highest emission efficiency is given by:

1. 1. Tungsten

   
   
   

   2. Thoriated tungsten

   
   
   

   3. Oxide coated cathode

   
   
   

   4. Cesium

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: C

   NA

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