The OLTC (online tap changer) is installed on the high
voltage side.
For second part of your question, I would like you to think
and find the answer.
- MS
__________________
"All my technical advices in this forum must be consulted with and approved by a local registered professional engineer before implementation" - Mohammed Samad (Linkedin Profile: http://www.linkedin.com/in/msamad)
Is it an interview question or one came in your exam? Better study the fundamentals . If you read any basic book on transformers you could clear your doubts . Better start with your fundamentals before putting questions in this forum.