Advice required for Geology and Geography papers in CCE 2013
 

Mine optional subjects are Geology and Geography in CCE 2013.
I need advice from members. If question in Geography asks solve given question with suitable diagrams, thus, should diagram be made with pencil or boil point?
If question doesnt ask any diagram, it is based on purely on description, but one wants to make diagram is it good, i mean diagram can earn some extra marks? Or it will have negative impact on checker?