Question

SPOT THE ERROR :

He works at an University of Madras.

Answer 1

an is the error
in the sentence
He works at a university of Madras

Answer 2

Heya !!!

This is Your Answer.

Given Sentence :
He works at an University Of Madras.

We know that an is used before vowels and U is also a vowel. 
But, It is used used according to the sound produced by the first letter. 
In university, *U* produces a sound of *Y*, as (Yuniversity). So we write a before University.
Same case with *honest*, Here *H* is silent. So it starts with a sound of A or O (Awnest). Therefore, an is used before Honest.

Hence, The Correct Sentence is "He works at a University of Madras."
More Correct : "He works at the University of Madras" as it refers to a proper noun.

Hope It Helps