can i force my silent iphone to ring

Only if you have "Find my phone" installed and activated. In that case you could send a signal tone, which overrides the silent mode of your phone.

Display a message or play
a sound to help you find it.

Say you’ve just used Find My iPhone, and it turns out you left your iPhone at the doctor’s office. You can write a message and display it on your screen. Something like, “Oops, left my iPhone behind. Please call me at 408-555-0198.” Your message appears, even if the screen is locked. And if the map shows that your iPhone is nearby — perhaps in your office under a pile of papers — yet you still can’t find it, you can tell Find My iPhone to play a sound that overrides the volume or silent setting.

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Locate your missing iPhone with Find My iPhone.