How to turn off ringer when connected to particular wifi network Is it possible (in built or via an app) to silence the phone when it's connected to a particular wireless network, and then unsilence it when the network is out of range.

Use case : When I'm in the office on the company's wifi I want my phone to be quiet, but when I'm back home (or not connected to a wifi, e.g. outside) I want the ringer volume back.
This isn't built-in functionality, but it's something you could achieve with a trigger/event app such as Tasker. This kind of app runs in the background, and lets you configure certain actions to take (such as turning off the ringer) when certain events occur (such as seeing a particular Wi-Fi network). Tasker's not the only such app, but it's very complete and has some users who contribute to this site, which means that if you have questions setting it up you can probably get them answered here. See tasker.