Sample Space is the totality of all possible outcomes of an experiment.
Hence if the experiment was inspecting a light bulb, the only possible outcomes are that it is defective or not defective. Hence the sample space has two members, defective or not defective.
Events are said to be mutually exclusive if they cannot occur at the same time when an experiment is performed. Thus, if two events are mutually exclusive the acceptance of one precludes the acceptance of another.