Context: In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils. After Jedlik solved the technical problems of the continuous rotation with the invention of the commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for instructional purposes, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator, rotor and commutator. The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings.

Question: In what year did Jedlik begin experimenting with electromagnetism?
Answer: 1827

Question: Besides the stator and the communicator, what is an element of a DC motor?
Answer: rotor

Question: What did Jedlik call his earliest devices?
Answer: electromagnetic self-rotors

Question: What discovery solved the problem of continuous rotation?
Answer: commutator

Question: What did Jedlik's improved device eliminate the need for?
Answer: permanent magnets

Question: In what year did Jedlik begin experimenting with non-electromagnetism?
Answer: Unanswerable

Question: Besides the stator and the communicator, what is an element of a non-DC motor?
Answer: Unanswerable

Question:  What didn't Jedlik call his earliest devices?
Answer: Unanswerable

Question:  What discovery solved the problem of non-continuous rotation?
Answer: Unanswerable

Question:  What did Jedlik's improved device make the need for?
Answer: Unanswerable