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3. current electricity — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics3. current electricity1 Mark
MCQ
Assertion : Bending a wire does not effect electrical resistance.

Reason : Resistance of wire is proportional ot resistivity of material.

  • ✓
    If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
  • B
    If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
  • C
    If Assertion is correct but Reason is incorrect.
  • D
    If both the Assertion and Reason are incorrect.
✓

Answer

Correct option: A.
If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
a
Resistance wire $R = \rho \frac {I}{A}$, where $\rho $ is resistivity of material which does not depend on the geometry of wire. Since when wire is bent resistivity, length and area of cross-section do not change, therefore resistance of wire also remain same.

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