I live in an apartment with several fire sprinkler in the ceiling.

If the sprinkler goes off due to fire or malfunction, can I turn it off
after the fire is out? Is it the same valve near the water heater or is
there a different one?

Im more worry about water damage (to electronics and computers) than fire
damage. Perhaps because Ive never had a fire before and this is the first
time I moved to a place with fire sprinklers.

Alternately, is there a switch to cut off power to computers or other
devices when it senses water? This would reduce short-circuits caused by
water when the device is powered.