76. The resistance of a wire is R, It is stretched uniformly so that its length is doubled. The resistance now becomes

1. 1. 2 R

   
   
   

   2. R / 2

   
   
   

   3. 4 R

   
   
   

   4. R / 4

   
   
   

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   NA

   Correct Option: C

   NA

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77. For electroplating a spoon, it is placed in the voltameter at

1. 1. The position of anode

   
   
   

   2. The position of cathode

   
   
   

   3. Anywhere in the electrolyte

   
   
   

   4. None of the above

   
   
   

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   NA

   Correct Option: B

   NA

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78. If the length of a wire is doubled and its cross section is also doubled, then its resistance will

1. 1. Become one fourth

   
   
   

   2. Become four times

   
   
   

   3. Become two times

   
   
   

   4. Remain unchanged

   
   
   

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   NA

   Correct Option: D

   NA

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79. The capacity of a pure capacitor is 1 farad. In D.C. circuit, its effective resistance will be

1. 1. Zero

   
   
   

   2. Infinite

   
   
   

   3. 1 ohm

   
   
   

   4. 1 / 2 ohm

   
   
   

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   N/A

   Correct Option: B

   N/A

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80. Which of the following statements is not true?

1. 1. Conductance is the reciprocal of resistance and is measured is siemens

   
   
   

   2. Ohm's law is not applicable at very low and very high temperature

   
   
   

   3. Ohm's law is applicable to semiconductor

   
   
   

   4. Ohm's law is not applicable to electron tubes, discharge tubes and electrolytes

   
   
   

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   NA

   Correct Option: C

   NA

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