Lost your iPhone in the house and its on silent mode? No worries.
Simply log in to www.icloud.com on your computer.
Click on ‘Find my iPhone’ icon
Click on ‘All Devices’ at the top and select your lost device
Now click on ‘Play Sound’. The Phone will start ringing even if its on silent mode.
P.S – This feature works only if you are signed into iCloud on the phone and have Find My iPhone turned on in the iCloud settings.