176. Magnetic field due to an infinite current carrying wire varies with the distance (r) from the wire as

1. 1. r

   
   
   

   2. r²

   
   
   

   3. 1 / r

   
   
   

   4. 1 / r²

   
   
   

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   N/A

   Correct Option: C

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177. Constantan wire is used in making standard resistance because its

1. 1. Melting point is high

   
   
   

   2. Density is high

   
   
   

   3. Specific resistance is low

   
   
   

   4. Temperature coefficient of resistance is negligible

   
   
   

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   N/A

   Correct Option: D

   N/A

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178. Metals are good conductor of heat than insulator because

1. 1. Their atoms are relatively apart

   
   
   

   2. They contain free electrons

   
   
   

   3. They have reflecting surface

   
   
   

   4. None of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: B

   N/A

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179. If the electric current in a lamp decreases by 5% then the power output decreases by

1. 1. 25%

   
   
   

   2. 10%

   
   
   

   3. 5%

   
   
   

   4. 20%

   
   
   

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   N/A

   Correct Option: B

   N/A

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180. Which of the following units measure energy?

1. 1. Kilowatt-hour

   
   
   

   2. (volt)² (sec) (ohm)^-1

   
   
   

   3. (weber) (ampere)

   
   
   

   4. All of the above

   
   
   

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1. View Hint View Answer Discuss in Forum

   N/A

   Correct Option: D

   N/A

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