Unless otherwise permitted, type ac cable shall be secured within of every outlet box, junction box, cabinet, or fitting and at intervals not exceeding where installed on or across framing members.

Unless otherwise allowed, Type AC cable will be secured within 300 mm of every outlet box, junction box, cabinet, or fitting at intervals not exceeding 1.4  m where installed on or across framing members.

Explanation:

It is necessary for protection possible arc that may cause fire or electrical shocks.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.