The LFCS preparation guide pg.18 says that root privileges in the exam terminal can be obtained by entering 'sudo -i'. So anytime we run the sudo command we have to include the '-i' flag?
I do not know and it may depend on the platform used. These kinds of questions should be directed to the certification help staff, for which you should have a link, if you want to get an authoritative answer as any thing else may not be 100 percent right.
You should try the following two commands:
sudo ls -l
sudo -i ls -l
and see the difference. AFAIK, it is whether root's shell init files are read in and the current directory reset etc, kind of like su vs su - .
As coop said, you should ask the certification help staff. But running 'sudo -i ' won't hurt a bit, as it's a way to ensure that you are running commands under a certain command environment (root's in this case). You can confirm this by seeing the sudo man page where it's explained.