Prof Kailash Tyagi, Singh's guide, told PTI that the General arrived here last night and appeared for the viva in the morning.
General Singh is doing his doctorate on 'Security implications of rise of fundamentalism in Afghanistan: Its Global and Regional impact with special focus on Wakhan'.
Wakhan is an Afghan territory sandwiched between China and Pakistan.
Tyagi said Singh enrolled for his doctorate in 2009 and submitted the thesis in September last year.
He was the only candidate who appeared for viva today. His examiners included Prof S K Mishra who had come from Hissar for the purpose.
Tyagi expressed hope that the former Army Chief may be awarded the PhD in a couple of days.