Question 6A328

Laminated iron cores are crucial in devices like motors and generators (where armatures and fields exist) to combat eddy current losses. Eddy currents are unwanted circulating currents induced within a conductor by a changing magnetic field. In solid iron cores, these currents would flow freely, generating heat and reducing efficiency. Laminating the core involves constructing it from many thin sheets of iron, each insulated from the next. This insulation creates high-resistance barriers that effectively break up the potential large loops of eddy currents into many smaller, higher-resistance paths. By increasing the resistance the eddy currents encounter, their magnitude is significantly reduced, thereby lowering the energy lost as heat. Therefore, laminations both reduce the overall eddy current losses (A) and do so by offering a number of high-resistance paths to these currents (B). Both statements accurately describe the benefit and mechanism, making C the correct answer.