Final answer:
The winding connected to the welding and work leads in a welding transformer is the secondary winding. A changing magnetic field induces an electrical current in this winding, a process known as electromagnetic induction, used in transformer welding.
Step-by-step explanation:
The question implies a concept belonging to electromagnetic induction in Physics. The 'winding' that the question mentions appears to be a conductive coil or loop. When this winding is subjected to a changing magnetic field, an electrical current is induced in it based on Faraday's law of electromagnetic induction.
For example, in welding technology, the primary winding of the welding transformer gets the input power supply and produces a varying magnetic field around it. This magnetic field, when intercepted by the secondary winding (connected to the welding lead and work lead), induces an electric current in the secondary winding. This induced power is then used for creating a welding arc, eventually leading to the welding process. This process is known as transformer welding.
Learn more about Electromagnetic Induction