Firstly, the Banks are not that lame.
With the advent of CIBIL, Credit check has become more stringent.
When you apply for a Education Loan in one Bank, various details are captured by the bank and forwarded to CIBIL.
If you try to avail another Education loan from other bank, then will come to know about your existing loan and will turn down the application. If you have collateral, there is no problem.