Physics · Internal resistance, potential difference and emf of a cell, a combination of cells in series and parallel

A potentiometer wire has a length and resistance of . It is connected in series

A potentiometer wire has a length \( 2 \mathrm{m} \) and resistance of \( 10 \Omega \). It is connected in series with a Resistance of \( 990 \Omega \) and a cell of e.m.f. 2V. The potential gradient along the wire is

  • A. \( 0.01 \mathrm{v} / \mathrm{m} \)
  • B. \( 0.02 \mathrm{V} / \mathrm{m} \)
  • C. \( 0.03 \mathrm{V} / \mathrm{m} \)
  • D. \( 0.025 \mathrm{V} / \mathrm{m} \)

Step-by-step solution

Total circuit resistance = 990 Ω + 10 Ω = 1000 Ω. Current = 2 V / 1000 Ω = 0.002 A. Voltage across wire = 0.002 A × 10 Ω = 0.02 V. Potential gradient = 0.02 V / 2 m = 0.01 V/m.
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