If a copper wire was wrapped around the earth 10 times it would take how many seconds to turn the light on at the other end?

The correct answer is option 3):(1.3 sec)

Concept:

Impulse Electricity:

• Let us consider a pipe that has been filled with ping pong balls, if a ball is forced into the end of the pipe, the ball at the other end will be forced out.
• Each time a ball enters one end of the pipe, another ball is forced out the other end. This principle is also true for electrons in a wire. There are billions of electrons in a wire.
• If an electron enters one end of a wire, another electron is forced out of the other end. Again assume for the moment that a wire is long enough to be wound around the Earth 10 times.
• If a power source and switch were connected at one end of the wire and a light at the other end, the light would turn on the moment the switch was closed.
• But it would take light approximately 1.3 seconds to travel around the Earth 10 times.