Resistivity of a wire is _ ohm-m if 0.75A current flows through it by applying 1.5V potential difference, take length and cross section as 5m and 2.5 x 10^-7 m2.
Correct answer: A. 1 x 10^-7
- A. 1 x 10^-7
- B. 2.63 x 10^-8
- C. 19 x 10^-8
- D. 7.85 x 10^-8
Explanation
he resistivity (ρ) of a wire can be calculated using the formula:ρ = (R * A) / Lwhere R is the resistance, A is the cross-sectional area of the wire, and L is the length of the wire.Given that the current (I) is 0.75A and the potential difference (V) is 1.5V, we can use Ohm's law to calculate the resistance:R = V / I = 1.5V / 0.75A = 2ΩSubstituting the values of resistance (R), cross-sectional area (A), and length (L) into the resistivity formula:ρ = (2Ω * 2.5 x 10^-7 m^2) / 5m = 10^-7 Ω-mTherefore, the resistivity of the wire is:A) 1 x 10^-7 Ω-m
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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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