Here's a breakdown:
* "Electronics" is the subject of the sentence, and it's singular.
* "is" is the correct verb form for a singular subject in the present tense.
* "a subject" is the predicate nominative, describing what "Electronics" is.
* "about which" is a relative pronoun phrase modifying "subject." It's grammatically correct to use "which" after a preposition like "about."
* "you know very little" is a dependent clause that functions as the object of the verb "know."
Overall, the sentence is clear, concise, and grammatically sound.