A wire of uniform area of cross -section A length L and resistance R is cut into two parts. The resistivity of each part:
Correct answer: D. )D. remains same
- A. Become zero
- B. Is halved
- C. Is doubled
- D. )D. remains same
Explanation
Resistivity is a property of the material and depends mainly on its nature and temperature, not on the wire's length or cross-sectional area. Cutting the wire changes each piece's resistance, but not its resistivity, so students may incorrectly choose halved by applying the length relation to resistivity.
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About Resistance and Resistivity
Resistance measures opposition to current in a conductor and follows R = V/I for an ohmic conductor, while resistivity is an intrinsic property of the material. Questions use R = ρL/A, examine effects of length, cross-sectional area and temperature, and distinguish resistance, resistivity, conductance and conductivity.
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