n a PN junction, with no external voltage, the electric field between the acceptor and the donor ions is called asa.Barrierb.Peakc.Reversed.Threshold

The correct answer to the question about the electric field in a PN junction with no external voltage is a. Barrier.

Explanation:

In a PN junction, when the p-type material (which contains acceptor ions) is brought into contact with n-type material (which contains donor ions), a diffusion of carriers (holes from p-type and electrons from n-type) occurs. This diffusion leads to the formation of a depletion region where mobile charge carriers are absent. The space charge due to the fixed ionized donor and acceptor ions creates an electric field, which is referred to as the "barrier field" or "potential barrier." This barrier prevents further diffusion of charge carriers and establishes a built-in voltage across the junction.

In summary, the electric field established in the junction is known as the barrier, as it acts to create a potential difference that limits the flow of charge carriers under equilibrium conditions.