Practising questions is a must for any gate aspirant.I have collected previous years ECE gate papers which will be very useful for your preparation.Some of the papers have solutions as well.Try to solve them all and discuss the difficult questions with your friends or in facebook gate groups.
GATE 1991 to 2016 Papers are available below.
Here are the GATE ECE PAPERS from NPTEL and GATEFORUM websites.
I have also uploaded MOCK EXAM papers conducted by various online websites below: