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Capacitance of a capacitor made by a thin metal foil is 2 μF.If the foil is folded with paper of thickness 0.15 mm, dielectric constant of paper is 2.5 and width of paper is 400 mm,the length of foil will be

Options

  1. A0.34 m
  2. B1.33 m
  3. C13.4 m
  4. D33.9 m

Correct answer

D. 33.9 m

Step-by-step solution

If length of the foil is l then C = K ε 0 · l × b d ⇒ 2 × 1 0 - 6 = 2 · 5 × 8 · 8 5 × 1 0 - 1 2 × l ⁡ × 4 0 0 × 1 0 - 3 0 · 1 5 × 1 0 - 3 ⇒ l = 3 3 · 9 m

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