What is the warranty on iPads?

That's a little misleading. For the EU warranty the burden of proof that the problem is caused by a manufacturing defect is on you. Here is the full scoop on consumer rights-->Apple Products and Consumer Law Rights

One year.

https://www.apple.com/legal/warranty/

The warranty you have will be dictated by the laws of the country in which you purchased the device - and this may differ from the standard 12 month Apple warranty. For example, for countries within the European Union, the statutory warranty is two years.