An electric circuit is consisting of a cell, an ammeter and a nichrome wire of length l. If the length of the wire is reduced to half (l/2), then the ammeter reading

The resistance (R) of a conductor is directly proportional to its length (l) and inversely proportional to its cross-sectional area (A), expressed as R = ρl/A [1]. In an electric circuit with a constant voltage source (cell), Ohm's law states that the current (I) is inversely proportional to the resistance (I = V/R). When the length of the nichrome wire is reduced to half (l/2), its resistance also decreases to one-half of its original value. Since the resistance is halved, the current flowing through the circuit—and consequently the ammeter reading—gets doubled. This relationship is a fundamental principle of electricity where reducing the path length for electrons decreases the number of collisions with lattice ions, thereby lowering resistance and increasing current flow.

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > Activity 11.3 > p. 178