I don't know how but I am not able to ask a question. It shows that we are no longer accepting questions from this account. What should I have to do so that I can again ask my questions in forum??
The following post on Meta.SO post contains the official list of recommendations:
I strongly suspect in your case the reason wasn't a couple of "average" questions, it was the answers you posted that contained plagiarism and copied content without proper attribution. There was one answer I recall that had close to 10 downvotes before it was deleted (possibly by a moderator). If you read the above link those deleted answers still count against you.
On that answer you had multiple comments that you should attribute the source of the answer, which you decided not to heed. Not only did you not edit that post, you went ahead and did the same on another answer that now only contains attribution because someone else edited it after you failed to do so:
The Creative Commons Attribution license used by Wikipedia requires that. When you don't do it apart from not sitting well with other members it also has possible legal implications.
As for your current situation I can't view your deleted questions and answers but maybe you could try to improve some of your existing questions. For example the following question might have a bit more promise and possibly be re-opened if you gave a few examples of specific circuits where you'd seen the use of a MOSFET for power control and wondered why they would be chosen over an SCR:
And otherwise just go through your questions and answers and see if there's any way they can be improved and you'll possibly pick up a vote or two. But if you do get your post privilege back please don't go cutting & pasting material from anywhere into answers else without stating the source it came from! That, along with ignoring constructive comments on your posts seems to have led to this situation in the first place.
Edited to add that W5VO has pointed out in a comment that question bans are separate from answer bans. So it appears in this case you should be concentrating on improving questions but keep in mind the same could apply in the future to answers if too many are downvoted for similar reasons.