Answer:
When you want to extend an electrical wire for an apparatus, e.g., a lamp or a speaker.
Answer:
no you should not force a cpu into its socket.
Explanation: on an intel platform the pins are on the motherboard, therefore if you force it in it will damage the pins on the motherboard, and on AMD the pins are on the cpu itself so you can damage the extremely fragile pins on it, you can not shock your cpu however like the other answer.