Concept:For a uniform wire, the potential drops uniformly along its length. Use potential gradient or Ohm’s law.
Explanation:Given total resistance of the wire is
R=100 Ω and battery voltage is
V=6Â V.
Current through the wire:
I=RV​=1006​=0.06 A.
Resistance per metre of the wire:
3100​ Ω/m.
Resistance of a 50 cm segment:
R′=3100​×0.5=350​ Ω.
Potential difference across the 50 cm segment:
V′=IR′=0.06×350​=1 V.
Alternatively, potential gradient
=3 m6 V​=2 V/m.
For length 50 cm
=0.5Â m:
V′=2×0.5=1 V.
Answer:The potential difference between two points 50 cm apart on the wire is
1Â V.
Correct option: A. 1 V.