How to setup CRON job to run every 10 seconds in Linux?

To elaborate on Sougata Bose's answer, I think the OP wants a command to be run every 10 seconds from a start time; not 10 seconds after the first minute and every subsequent minute.

cron only has a resolution of 1 minute (there are other tools I think that may have finer resolutions but they are not standard on unix).

Therefore, to resolve your issue you need 60 seconds / 10 seconds = 6 cron jobs, each with a sleep.

e.g. run crontab -e and add the following lines to your chosen editor:

* * * * * ( /usr/bin/wget http://api.us/application/ )  * * * * * ( sleep 10 ; /usr/bin/wget http://api.us/application/ )  * * * * * ( sleep 20 ; /usr/bin/wget http://api.us/application/ )  * * * * * ( sleep 30 ; /usr/bin/wget http://api.us/application/ )  * * * * * ( sleep 40 ; /usr/bin/wget http://api.us/application/ )  * * * * * ( sleep 50 ; /usr/bin/wget http://api.us/application/ )  

Another option is to edit your crontab with crontab -e and write:

* * * * * for i in {1..6}; do /usr/bin/wget http://api.us/application/ & sleep 10; done

*/10 * * * * will run every 10 min.
*/10 * * * * * will run every 10 sec.

You can checkout the cron editor for more options.