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Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectromagnetic Induction

An inductor-coil with an inductance of 17 mH is fabricated using a copper wire that has a length of 100 m and a cross-sectional area of 1 mm ^2 . Determine the time constant of the circuit when this inductor is connected across an ideal battery. The resistivity of copper is 1.7 10⁻⁸ m .

Options

  1. A0.01 s
  2. B1.0 s
  3. C0.001 s
  4. D0.1 s

Correct answer

A. 0.01 s

Step-by-step solution

Resistance of the copper wire is given by R = l A Substituting the given values: R = 1.7 10⁻⁸ 100 1 10⁻⁶ = 1.7 The time constant of the LR circuit is given by = L R Substituting L = 17 mH = 17 10⁻³ H and R = 1.7 : = 17 10⁻³ 1.7 = 10 10⁻³ s = 0.01 s

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