Full GATE Electronics and Communication papers, one page per year. Every question has the answer from the official key and a worked solution, grouped by the sections of the EC syllabus.
Set by IIT Guwahati. 42 MCQ, 10 MSQ and 13 NAT questions.
Set by IIT Roorkee. 39 MCQ, 14 MSQ and 12 NAT questions.
Set by IISc Bengaluru. 39 MCQ, 8 MSQ and 18 NAT questions.
Set by IIT Kanpur. 45 MCQ, 4 MSQ and 16 NAT questions.
For the ideas behind these questions, see GATE ECE by subject.