How to be virus free using a flash drive?

depending on the virus - it can spread to flash drives/floppies/hard drives without you doing anything

A virus can be loaded into the computer by just plugging an infected flash drive because the computer automatically reads the drive even without prompting the user. This is how the computer knows that a flash drive has been attached and how the files could be opened (a window usually opens asking the user how he wishes to proceed). It is always best to have an anti-virus software scan the flash drive before proceeding.

Yes a virus can infect a flash drive without copying any files, just by plugging it in.

To make sure your system doesn't get infected make sure you have up-to-date anti-virus software. Some anti-virus vendors offer special software that you can install on your flash drive that when ran, will scan the driver for viruses.

if someone loaded a file that executes on activation of the flash drive.

yes,some viruses affecting on autorun.inf file , it will load to system without opening the flash drives

i use a flash drive and never had a problem i just scan it with the rest of my system.

no u can format the drive to wipe it clean or quarentine a file that you require just dont copy files to pc