I can’t help specifically with this, but I certainly would advise being prepared for the questions listed and more. Try to think of why you want to apply to Barclays and not just (because I’m a graduate and saw you scheme! – try to think of something that will impress them but is near the truth – perhaps something like “Barclays has been in the financial sector for well over 300 years, so is the biggest established banking company. I feel this is the best company to work for” etc