Dear all :
When we use Capactor 1000pf/50V , 50V is rated voltage.
DC work voltage can't exceed 50v before damage(here we don't consider safe voltage range (vrated/2=25v)),
1. if apply AC voltage , how about Vpp is safe (we also don't consider safe
voltage range) ?
2. If we apply surge voltage , how many voltage can accept in theory and
practical ?
You have to consult a manufacturers datasheet. The AC and surge specification must be expected to be different depending on the capacitor type. You may get surge specification like 2.5 * UR for 1 minute with low voltage ceramic caps.