Hello,

First, your total marks are calculated which is the sum of Theory + lab (ratio of credits).

Following are the criteria by which grades are awarded for a subject-

1. Mean marks of class strength are calculated-'M'.

2. Standard deviation is calculated central to mean -'E'.

If your total(Theory+lab) marks are greater than M+1.5*E you get S.

A if your total marks are greater M+0.5*E but less than M+1.5*E

B if your mark is greater than  M-0.5*E but less than  M+0.5*E

C if your mark is less than  M-0.5*E but greater than M-1.5*E

Similarly for other grades marks can be calculated. However, if no student is able to pass S grade barrier then top 3 students are awarded S grade.

Hope this helps.