Which of these changes would decrease the resistance of a metallic conductor?
Increasing the thickness of the conductor
The resistance of a metallic conductor is given by \(R = \frac{\rho L}{A}\), where ρ is the resistivity, L is the length and A is the cross-sectional area.
Resistance is inversely proportional to the area A. Increasing the thickness of the wire increases A, so R decreases — a thicker wire offers more paths for the free electrons.
Increasing the length increases R, because R is directly proportional to L.
Increasing the temperature of a metal increases R, because the lattice ions vibrate more and scatter the electrons more often (resistivity rises).
Decreasing the thickness reduces A, which increases R.
Hence, the answer is Increasing the thickness of the conductor.
Similar Questions
The SI unit of resistivity is:
When a cylindrical wire made of a new alloy is stretched to double its original length, its resistance increases by a factor of four. If a second wire of the same alloy is shaped into a flat ribbon of identical length but half the original cross-sectional area, which property stays constant between the two wires?
A wire is stretched uniformly at a constant temperature without changing its material. Which of the following physical quantities remains unchanged?
Important Questions from Resistance and Resistivity
Which of the following metals has the lowest electrical resistivity?
A uniform wire of resistance 9Ω is bent in the form of an equilateral triangle. Find the effective resistance across a side of the triangle.
The value of carbon resistance is 54 × 103 Ω. The percentage tolerance is 5%. What is the colour code sequence of carbon resistance?
Which of the following relations are wrong?
I. The specific conductance is given by the relation \(k = \frac{1}{R}\left( {l/A} \right)\)
II. The equivalent conducting is given by the relation \(\lambda = \frac{{100\;K}}{C}\)
III. The specific resistance is given by the relation \(\rho = \frac{{Rl}}{A}\)
A current is flowing through a metallic wire. If the wire is heated, which quantities change?
