2004 AIPMT Current ElectricityPotential Drop along a Uniform Wire Easy Question 117 of 130 in Current Electricity

A 6 volt battery is connected to the terminals of a three metre long wire of uniform thickness and resistance of 100 ohm. The difference of potential between two points on the wire separated by a distance of 50 cm will be :-

A 3 V
B 1 V
C 1.5 V
D 2 V

The answer is B.

Solution

The wire is uniform, so the potential drops uniformly along its length (we take the battery to have negligible internal resistance).
Potential gradient $= \dfrac{6\ \text{V}}{300\ \text{cm}} = \dfrac{1}{50}$ V/cm
Voltage across 50 cm $= \dfrac{6}{300} \times 50 = 1$ volt
So the potential difference between two points 50 cm apart is 1 V.

Concept Potential gradient along a uniform wire

Current Electricity in past papers

130 questions from this chapter have appeared across 27 exam years.