A wire of uniform area of cross-section A length L and resistance R is cut into two parts. Resistivity of each part _________________?
Correct answer: A. remains the same
- A. remains the same
- B. is doubled
- C. is halved
- D. becomes zero
Explanation
Resistivity is a property of the material, represented by ρ in R = ρL/A, so cutting the wire changes its length and resistance but not its resistivity. Option c, halved, incorrectly applies the change in length to the material property.
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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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