My friend had the opportunity to appear for the written test and interview at IIT Hyderabad for Ph.D. this year in July for the Communication and Signal Processing Electrical Engineering department. There were 2 tests conducted out of which the first comprised 6 questions. 5 questions were based on probability and random processes while the other one was on signal and systems. The test lasted for 2 hours. The questions asked in this fest were quite difficult and tested functions of one and two random variables.

For the second test, a transfer junction was provided and 9 questions were asked related to it. The entire test lasted for an hour. The questions in the test were comparatively easier than those of the first. The only challenge was to complete the lengthy questions in a short duration of 1 hour. 

Out of the 60 applicants that appeared with my friend, only 8 were shortlisted for the interview. 

Overall, the professors were very supportive and helped students wherever necessary. The duration of the interview is around 20 minutes.