If the resistivity and cross-sectional area of a metallic wire remain constant, then on increasingits length the resistance of the wire will
Correct answer: A. increase.
- A. increase.
- B. decrease.
- C. become zero.
- D. remain constant.
Explanation
The resistance (R) of a metallic wire is directly proportional to its length (L) and resistivity (ρ), and inversely proportional to its cross-sectional area (A). This relationship is described by the formula:R = ρL/AWhere: * R = Resistance * ρ = Resistivity (a material property) * L = Length * A = Cross-sectional AreaAccording to the question, the resistivity (ρ) and cross-sectional area (A) of the metallic wire remain constant. If you increase the length (L) while ρ and A are held constant, the resistance (R) must also increase, as they are directly proportional.
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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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