Current transformers are connected in __________ with the line.

Current transformers are connected in series with the line to accurately measure current flowing through the conductor. This series connection allows the transformer to accurately replicate the current, reducing it to a lower level that can be safely measured by metering and protective devices.

In this arrangement, the entire current of the line flows through the primary winding of the transformer while the secondary winding produces a lower current that is proportional to the primary current. This relationship is critical for the transformers to function correctly and ensure precise reading and monitoring of the electrical system's performance.

Using a series connection also facilitates the operation of protection relays and metering systems, as these devices require the current to pass through to operate effectively. In contrast, current transformers connected in parallel would not provide accurate current measurements, as they would not allow the line current to flow through the transformer as needed for correct operation.