As you have asked for the sample interview questions for the preparation of the interview of the Union Bank of India, I am giving you information about it, check below for the details
I am providing you with some of the general banking questions which will help you in interview, check below for the details

What is NABARD and it functions ?(In detail)
NABARD was established by an act of Parliament on 12 July 1982 to implement the National Bank for Agriculture and Rural Development Act 1981.
What is banking ?
Different types of Banks?
What is profits?
What are the different types of deposits in bank?
What is interest rate on saving account in nationalized banks?
Answer: 4%
Which bank is giving more than 4% interest rate?
Answer: BMB 4.5%
What is NPA?(RESEARCH ABOUT THIS IN DETAIL)
SARFAESI Act 2002?
What is ARC( asset reconstruction company)? in detail
What is Banking Ombudsman Scheme?
What is current CRR and reverse repo rate,repo,slr?
What is NEFT or RTGS ?(in detail)
When RTGS started?
What is NTDL?
What is stale cheque?(all types of cheques)
What is a post-dated cheque?
What is CTS?
What is current account deficit? How does it increase?
What is CASA?
What is GDP?