Physics · Conductors and insulators, dielectrics and electric polarization

Consider a long conductor, the middle of which is earthed. If the potential diff

Consider a long conductor, the middle of which is earthed. If the potential difference across the two ends of the conductor is \( 220 \mathrm{V} \), then what is the potential at the ends and the middle point?

  • A. \( 220 V \) all over the conductor
  • B. \( 110 V \) and \( -110 V \) at ends and \( 0 V \) at the mid point
  • C. \( 0 V \) at ends and \( 220 V \) at midpoint
  • D. \( -220 \mathrm{V} \) all over the conductor

Step-by-step solution

The conductor is long and earthed at the middle, meaning the midpoint is at 0 V potential. The potential difference between the two ends is given as 220 V. Since the conductor is symmetric and the middle is grounded, the potentials at the ends are equal in magnitude but opposite in sign relative to the midpoint. Therefore, one end is at +110 V and the other at -110 V, with the midpoint at 0 V.
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