Answer:
a. The circuit diagram is
An insulated copper wire is twisted around coil C, with the ends of the copper wire being linked to a battery at either end of the coil. As a result, an electromagnet is utilized in place of the soft iron core.
b) When working in a scrap yard, electromagnetic cranes are employed in order to separate the copper from the iron. The electromagnet is powered by allowing electricity to pass through it, which aids in the removal of iron scraps from the scrap yard once they have been collected.