What is the difference between 试验 and 实验? Both 试验 and 实验 seems to be translated into "experiment". What is the difference between the two words? Can they be used interchangeably or not?
实验 is used for operations and activities done to test a scientific theory or hypothesis. An example: 经过反复实验，证明这一结论是正确的

试验 is used to inspect the function or effect of some physical thing (something that already exists). It's typically done in some lab.
Some examples:


新农药要经过反复试验才能推广
试验新机器
新办法试验后推广