Which one of the following statements is not correct ?

Statement 4 is incorrect because in a standard domestic electric supply, the wire with green insulation is the earth wire, not the live wire. The live wire is typically insulated with red or brown color, while the neutral wire is black or blue. Statement 1 is correct as electric motors convert electrical energy into mechanical energy through the interaction of magnetic fields. Statement 2 is correct because electric generators operate on the principle of electromagnetic induction, where mechanical motion in a magnetic field induces an electric current. Statement 3 is also correct; for a circular loop or coil, the magnetic field lines at the center appear as straight lines. In a long coil or solenoid, these lines are parallel straight lines, indicating a uniform magnetic field inside [2].

Sources

1. [2] Science , class X (NCERT 2025 ed.) > Chapter 12: Magnetic Effects of Electric Current > 12.2.3 Magnetic Field due to a Current through a Circular Loop > p. 200