What type of field travels through space after being detached from the current-carrying rod of an antenna?

The radiation field is the correct answer because it refers to the electromagnetic waves that propagate through space after being generated by the oscillating electric and magnetic fields associated with the current flowing in an antenna. When the antenna transmits energy, the changing currents produce variations in electric and magnetic fields, which then extend outward from the antenna as electromagnetic waves, commonly known as radiation.

This phenomenon is central to how antennas function, as they convert electrical energy into electromagnetic radiation that can travel over long distances. These radiation fields can carry information, which is the basis for all wireless communications. Unlike the electric and magnetic fields, which may exist in the vicinity of the antenna and are associated with the immediate energy distribution, the radiation field represents the energy that is effectively radiated away from the antenna and can be received by remote devices.

In contrast, induction fields, electric fields, and magnetic fields are typically associated with static or quasi-static conditions that are either due to stored energy or current distributions but do not represent the propagating nature of the electromagnetic radiation emitted from an antenna.