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Current Electricity — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsCurrent Electricity1 Mark
Question
For two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both A and R are true, and R is the correct explanation of A.
  2. Both A and R are true, but R is not the correct explanation of A.
  3. A is true, but R is false.
  4. A is false, and R is also false.
Assertion: Material used in the construction of a standard resistance is constantan or manganin.
Reason: Temperature coefficient of constantan is very small.
✓

Answer

  1. Both A and R are true, and R is the correct explanation of A.
Explanation:

These alloys (constantan or manganin) are used for making standard resistance because they possess high resistivity and low temperature coefficient of resistance.

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